FindGTest: Avoid macro name collision

Use two _'s for private function/macro names rather than one. This
avoids a potential collision if a function/macro with no leading _ that
otherwise matches the name of a private function/macro also overrides a
built-in function or is defined twice.

Modules/FindGTest.cmake

@@ -75,7 +75,7 @@
 
 include(${CMAKE_CURRENT_LIST_DIR}/GoogleTest.cmake)
 
-function(_gtest_append_debugs _endvar _library)
+function(__gtest_append_debugs _endvar _library)
     if(${_library} AND ${_library}_DEBUG)
         set(_output optimized ${${_library}} debug ${${_library}_DEBUG})
     else()
@@ -84,7 +84,7 @@ function(_gtest_append_debugs _endvar _library)
     set(${_endvar} ${_output} PARENT_SCOPE)
 endfunction()
 
-function(_gtest_find_library _name)
+function(__gtest_find_library _name)
     find_library(${_name}
         NAMES ${ARGN}
         HINTS
@@ -95,7 +95,7 @@ function(_gtest_find_library _name)
     mark_as_advanced(${_name})
 endfunction()
 
-macro(_gtest_determine_windows_library_type _var)
+macro(__gtest_determine_windows_library_type _var)
     if(EXISTS "${${_var}}")
         file(TO_NATIVE_PATH "${${_var}}" _lib_path)
         get_filename_component(_name "${${_var}}" NAME_WE)
@@ -109,18 +109,18 @@ macro(_gtest_determine_windows_library_type _var)
     endif()
 endmacro()
 
-function(_gtest_determine_library_type _var)
+function(__gtest_determine_library_type _var)
     if(WIN32)
         # For now, at least, only Windows really needs to know the library type
-        _gtest_determine_windows_library_type(${_var})
-        _gtest_determine_windows_library_type(${_var}_RELEASE)
-        _gtest_determine_windows_library_type(${_var}_DEBUG)
+        __gtest_determine_windows_library_type(${_var})
+        __gtest_determine_windows_library_type(${_var}_RELEASE)
+        __gtest_determine_windows_library_type(${_var}_DEBUG)
     endif()
     # If we get here, no determination was made from the above checks
     set(${_var}_TYPE UNKNOWN PARENT_SCOPE)
 endfunction()
 
-function(_gtest_import_library _target _var _config)
+function(__gtest_import_library _target _var _config)
     if(_config)
         set(_config_suffix "_${_config}")
     else()
@@ -181,15 +181,15 @@ mark_as_advanced(GTEST_INCLUDE_DIR)
 if(MSVC AND GTEST_MSVC_SEARCH STREQUAL "MD")
     # The provided /MD project files for Google Test add -md suffixes to the
     # library names.
-    _gtest_find_library(GTEST_LIBRARY            gtest-md  gtest)
-    _gtest_find_library(GTEST_LIBRARY_DEBUG      gtest-mdd gtestd)
-    _gtest_find_library(GTEST_MAIN_LIBRARY       gtest_main-md  gtest_main)
-    _gtest_find_library(GTEST_MAIN_LIBRARY_DEBUG gtest_main-mdd gtest_maind)
+    __gtest_find_library(GTEST_LIBRARY            gtest-md  gtest)
+    __gtest_find_library(GTEST_LIBRARY_DEBUG      gtest-mdd gtestd)
+    __gtest_find_library(GTEST_MAIN_LIBRARY       gtest_main-md  gtest_main)
+    __gtest_find_library(GTEST_MAIN_LIBRARY_DEBUG gtest_main-mdd gtest_maind)
 else()
-    _gtest_find_library(GTEST_LIBRARY            gtest)
-    _gtest_find_library(GTEST_LIBRARY_DEBUG      gtestd)
-    _gtest_find_library(GTEST_MAIN_LIBRARY       gtest_main)
-    _gtest_find_library(GTEST_MAIN_LIBRARY_DEBUG gtest_maind)
+    __gtest_find_library(GTEST_LIBRARY            gtest)
+    __gtest_find_library(GTEST_LIBRARY_DEBUG      gtestd)
+    __gtest_find_library(GTEST_MAIN_LIBRARY       gtest_main)
+    __gtest_find_library(GTEST_MAIN_LIBRARY_DEBUG gtest_maind)
 endif()
 
 include(${CMAKE_CURRENT_LIST_DIR}/FindPackageHandleStandardArgs.cmake)
@@ -197,14 +197,14 @@ FIND_PACKAGE_HANDLE_STANDARD_ARGS(GTest DEFAULT_MSG GTEST_LIBRARY GTEST_INCLUDE_
 
 if(GTEST_FOUND)
     set(GTEST_INCLUDE_DIRS ${GTEST_INCLUDE_DIR})
-    _gtest_append_debugs(GTEST_LIBRARIES      GTEST_LIBRARY)
-    _gtest_append_debugs(GTEST_MAIN_LIBRARIES GTEST_MAIN_LIBRARY)
+    __gtest_append_debugs(GTEST_LIBRARIES      GTEST_LIBRARY)
+    __gtest_append_debugs(GTEST_MAIN_LIBRARIES GTEST_MAIN_LIBRARY)
     set(GTEST_BOTH_LIBRARIES ${GTEST_LIBRARIES} ${GTEST_MAIN_LIBRARIES})
 
     find_package(Threads QUIET)
 
     if(NOT TARGET GTest::GTest)
-        _gtest_determine_library_type(GTEST_LIBRARY)
+        __gtest_determine_library_type(GTEST_LIBRARY)
         add_library(GTest::GTest ${GTEST_LIBRARY_TYPE} IMPORTED)
         if(TARGET Threads::Threads)
             set_target_properties(GTest::GTest PROPERTIES
@@ -218,17 +218,17 @@ if(GTEST_FOUND)
             set_target_properties(GTest::GTest PROPERTIES
                 INTERFACE_INCLUDE_DIRECTORIES "${GTEST_INCLUDE_DIRS}")
         endif()
-        _gtest_import_library(GTest::GTest GTEST_LIBRARY "")
-        _gtest_import_library(GTest::GTest GTEST_LIBRARY "RELEASE")
-        _gtest_import_library(GTest::GTest GTEST_LIBRARY "DEBUG")
+        __gtest_import_library(GTest::GTest GTEST_LIBRARY "")
+        __gtest_import_library(GTest::GTest GTEST_LIBRARY "RELEASE")
+        __gtest_import_library(GTest::GTest GTEST_LIBRARY "DEBUG")
     endif()
     if(NOT TARGET GTest::Main)
-        _gtest_determine_library_type(GTEST_MAIN_LIBRARY)
+        __gtest_determine_library_type(GTEST_MAIN_LIBRARY)
         add_library(GTest::Main ${GTEST_MAIN_LIBRARY_TYPE} IMPORTED)
         set_target_properties(GTest::Main PROPERTIES
             INTERFACE_LINK_LIBRARIES "GTest::GTest")
-        _gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "")
-        _gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "RELEASE")
-        _gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "DEBUG")
+        __gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "")
+        __gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "RELEASE")
+        __gtest_import_library(GTest::Main GTEST_MAIN_LIBRARY "DEBUG")
     endif()
 endif()