[cmake] Make gtest macro definitions a part the library interface

[labath]

Summary

These definitions are needed by any file which uses gtest. Previously we
were adding them in the add_unittest function, but over time we've
accumulated libraries (which don't go through add_unittest) building on
gtest and this has resulted in proliferation of the definitions.

Making this a part of the library interface enables them to be managed
centrally. This follows a patch for -Wno-suggest-override (D84554) which
took a similar approach.

[ldionne]

Can you confirm that all the targets that need to "link" (in the CMake sense) against gtest use the gtest CMake target?

[labath]

In D84748#2178809, @ldionne wrote:

Can you confirm that all the targets that need to "link" (in the CMake sense) against gtest use the gtest CMake target?

I wouldn't use the word "confirm" but I did check that I am able to run test for subprojects I have modified (in their default configs) and that no other subprojects define these macros.

lldb/unittests/TestingSupport/Symbol/CMakeLists.txt

 set_property(DIRECTORY PROPERTY EXCLUDE_FROM_ALL ON)
 add_lldb_library(lldbSymbolHelpers
   YAMLModuleTester.cpp
   )
 
-# Our current version of gtest does not properly recognize C++11 support
-# with MSVC, so it falls back to tr1 / experimental classes.  Since LLVM
-# itself requires C++11, we can safely force it on unconditionally so that
-# we don't have to fight with the buggy gtest check.
-target_compile_definitions(lldbSymbolHelpers PUBLIC
-  -DGTEST_LANG_CXX11=1
-  -DGTEST_HAS_TR1_TUPLE=0)
 target_include_directories(lldbSymbolHelpers PUBLIC
   ${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest/include
   ${LLVM_MAIN_SRC_DIR}/utils/unittest/googlemock/include)

llvm/cmake/modules/AddLLVM.cmake

 endfunction(add_llvm_implicit_projects)
 
 # Generic support for adding a unittest.
 function(add_unittest test_suite test_name)
   if( NOT LLVM_BUILD_TESTS )
     set(EXCLUDE_FROM_ALL ON)
   endif()
 
-  # Our current version of gtest uses tr1/tuple which is deprecated on MSVC.
-  # Since LLVM itself requires C++14, we can safely force it off.
-  add_definitions(-DGTEST_HAS_TR1_TUPLE=0)
-
   include_directories(${LLVM_MAIN_SRC_DIR}/utils/unittest/googletest/include)
   include_directories(${LLVM_MAIN_SRC_DIR}/utils/unittest/googlemock/include)
-  if (NOT LLVM_ENABLE_THREADS)
-    list(APPEND LLVM_COMPILE_DEFINITIONS GTEST_HAS_PTHREAD=0)
-  endif ()
 
   if (SUPPORTS_VARIADIC_MACROS_FLAG)
     list(APPEND LLVM_COMPILE_FLAGS "-Wno-variadic-macros")
   endif ()
   # Some parts of gtest rely on this GNU extension, don't warn on it.
   if(SUPPORTS_GNU_ZERO_VARIADIC_MACRO_ARGUMENTS_FLAG)
     list(APPEND LLVM_COMPILE_FLAGS "-Wno-gnu-zero-variadic-macro-arguments")
   endif()

llvm/lib/Testing/Support/CMakeLists.txt

-add_definitions(-DGTEST_LANG_CXX11=1)
-add_definitions(-DGTEST_HAS_TR1_TUPLE=0)
-
 add_llvm_library(LLVMTestingSupport
   Annotations.cpp
   Error.cpp
   SupportHelpers.cpp
 
   BUILDTREE_ONLY
   
   ADDITIONAL_HEADER_DIRS

llvm/utils/unittest/CMakeLists.txt

 # Where gtest's .h files can be found.
 include_directories(
   googletest/include
   googletest
   googlemock/include
   googlemock
   )
 
-# Gtest 1.8.0 uses tr1/tuple which is deprecated on MSVC, so we force it off.
-add_definitions(-DGTEST_HAS_TR1_TUPLE=0)
-
 if(WIN32)
   add_definitions(-DGTEST_OS_WINDOWS=1)
 endif()
 
 # Google Test requires headers which need _ALL_SOURCE to build on AIX
 if (UNIX AND ${CMAKE_SYSTEM_NAME} MATCHES "AIX")
   remove_definitions("-D_XOPEN_SOURCE=700")
   add_definitions("-D_ALL_SOURCE")
 endif()
 
 if(SUPPORTS_VARIADIC_MACROS_FLAG)
   add_definitions("-Wno-variadic-macros")
 endif()
 if(SUPPORTS_GNU_ZERO_VARIADIC_MACRO_ARGUMENTS_FLAG)
   add_definitions("-Wno-gnu-zero-variadic-macro-arguments")
 endif()
 if(CXX_SUPPORTS_COVERED_SWITCH_DEFAULT_FLAG)
   add_definitions("-Wno-covered-switch-default")
 endif()
 
 set(LLVM_REQUIRES_RTTI 1)
 add_definitions( -DGTEST_HAS_RTTI=0 )
 
-if (NOT LLVM_ENABLE_THREADS)
-  add_definitions( -DGTEST_HAS_PTHREAD=0 )
-endif()
-
 find_library(LLVM_PTHREAD_LIBRARY_PATH pthread)
 if (LLVM_PTHREAD_LIBRARY_PATH)
   list(APPEND LIBS pthread)
 endif()
 
 add_llvm_library(gtest
   googletest/src/gtest-all.cc
   googlemock/src/gmock-all.cc

 # The googletest and googlemock sources don't presently use the 'override'
 # keyword, which leads to lots of warnings from -Wsuggest-override. Disable
 # that warning here for any targets that link to gtest.
 if(CXX_SUPPORTS_SUGGEST_OVERRIDE_FLAG)
   add_definitions("-Wno-suggest-override")
   set_target_properties(gtest PROPERTIES INTERFACE_COMPILE_OPTIONS "-Wno-suggest-override")
 endif()
 
+# Gtest 1.8.0 uses tr1/tuple which is deprecated on MSVC, so we force it off.
+target_compile_definitions(gtest PUBLIC GTEST_HAS_TR1_TUPLE=0)
+
+if (NOT LLVM_ENABLE_THREADS)
+  target_compile_definitions(gtest PUBLIC GTEST_HAS_PTHREAD=0)
+endif ()
+
 add_subdirectory(UnitTestMain)
 
 # When LLVM_LINK_LLVM_DYLIB is enabled, libLLVM.so is added to the interface
 # link libraries for gtest and gtest_main.  This means that any target, like
 # unittests for example, that links against gtest will be forced to link
 # against libLLVM.so.  In some cases we may want to statically unittests if they
 # need access to symbols that are marked private in libLLVM.so.  The only
 # way we can make this work is to remove libLLVM.so from the list of interface