Update GTest/GMock structure, apply some fixes

[alexezeder]

• all GTest/GMock files moved to test/gtest directory
• CMakeLists.txt created in test/gtest from CMakeLists.txt in test
• GTest/GMock target in CMake renamed to gtest (was gmock)
• CMake gtest target updated to export includes as "gtest/gtest.h" or "gmock/gmock.h" only
• includes in tests updated: "gtest.h" -> "gtest/gtest.h", "gmock.h" -> "gmock/gmock.h"
• removed duplications of target_include_directories for GTest/GMock directories (CMake manages them)
• .clang-format file added into test/gtest directory to prevent formatting there
• obsolete GTEST_LANG_CXX11 compile definition setting removed
• std::is_trivially_copy_constructible for GCC 4.8 & 4.9 fixed properly

[vitaut]

Thanks for the PR. In general looks good but let's use the directory structure generated by the fuse script (not introduce include directories) and use gtest instead of gmock as the top-level directory since the gmock component is way less important:

gtest/
  gtest/gtest.h
  gmock/gmock.h
  gmock-gtest-all.cc

[alexezeder]

use gtest instead of gmock as the top-level directory since the gmock component is way less important

Maybe I should also rename CMake target then?

[vitaut]

Maybe I should also rename CMake target then?

Good idea.

[alexezeder]

let's use the directory structure generated by the fuse script (not introduce include directories)

gtest/
  gtest/gtest.h
  gmock/gmock.h
  gmock-gtest-all.cc

Sorry for breaking your message into pieces, but I just realized that include directory was introduced on purpose. As we saw here, this structure makes compilers use GTest/GMock includes as a relative path, but not a system, while building gmock-gtest-all.cc, because of "", not <> includes. At the same time, only the system includes allows us to get rid of potential compiler warnings. Of course, there was a problem with std::pod only, but who knows what else suspicious various compilers can find inside the GTest library.

[alexezeder]

On the other hand, maybe warnings (not errors, if no other CXX_FLAGS passed to CMake) from the GTest library, while building (currently) gmock CMake target, are not so bad to change the structure...

[vitaut]

maybe warnings (not errors, if no other CXX_FLAGS passed to CMake) from the GTest library, while building (currently) gmock CMake target, are not so bad to change the structure...

Yeah, I think warnings are OK.

[alexezeder]

I updated this PR with a few additional updates like a fix for std::is_pod usage.

Also, there are 2 places I want to discuss:

1. fmt/test/CMakeLists.txt

   Lines 45 to 50 in 342973b

   	# Workaround GTest bug https://github.com/google/googletest/issues/705.
   	check_cxx_compiler_flag(
   	-fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
   	if (HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
   	target_compile_options(test-main PUBLIC -fno-delete-null-pointer-checks)
   	endif ()

   
   maybe it should be moved to the new CMakeLists.txt file with this flag applied to gtest CMake target? Because there are some fixes for MSVC already:
   

   fmt/test/gtest/CMakeLists.txt

   Lines 20 to 27 in 9e5072f

   	if (MSVC)
   	# Disable MSVC warnings of _CRT_INSECURE_DEPRECATE functions.
   	target_compile_definitions(gtest PRIVATE _CRT_SECURE_NO_WARNINGS)
   	if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   	# Disable MSVC warnings of POSIX functions.
   	target_compile_options(gtest PUBLIC -Wno-deprecated-declarations)
   	endif ()
   	endif ()

2. fmt/test/CMakeLists.txt

   Lines 52 to 56 in 342973b

   	# Use less strict pedantic flags for the tests because GMock doesn't compile
   	# cleanly with -pedantic and -std=c++98.
   	if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
   	#set(PEDANTIC_COMPILE_FLAGS -Wall -Wextra -Wno-long-long -Wno-variadic-macros)
   	endif ()

   
   maybe it should be removed? 😄

[vitaut]

Awesome, thanks!

[alexezeder]

Great, but what do you think about #2256 (comment)? 🙂

[vitaut]

what do you think about #2256 (comment)?

Both suggestions look reasonable to me.