From 2844167ff99edb63f629c9768ea1f3f94ebfb8fe Mon Sep 17 00:00:00 2001
From: Eric Fiselier <eric@efcs.ca>
Date: Thu, 5 Apr 2018 18:31:03 -0600
Subject: [PATCH] Fix #564 - gmock/gmock.h not found in benchmark tests.

---
 cmake/HandleGTest.cmake | 58 ++++++++++++++++++++++++++++-------------
 1 file changed, 40 insertions(+), 18 deletions(-)

diff --git a/cmake/HandleGTest.cmake b/cmake/HandleGTest.cmake
index 11528b89..3ebe9f32 100644
--- a/cmake/HandleGTest.cmake
+++ b/cmake/HandleGTest.cmake
@@ -54,40 +54,62 @@ macro(build_external_gtest)
       )
 
   ExternalProject_Get_Property(googletest install_dir)
-
-  add_library(gtest UNKNOWN IMPORTED)
-  add_library(gtest_main UNKNOWN IMPORTED)
+  set(GTEST_INCLUDE_DIRS ${install_dir}/include)
+  file(MAKE_DIRECTORY ${GTEST_INCLUDE_DIRS})
 
   set(LIB_SUFFIX "${CMAKE_STATIC_LIBRARY_SUFFIX}")
   set(LIB_PREFIX "${CMAKE_STATIC_LIBRARY_PREFIX}")
-
   if("${GTEST_BUILD_TYPE}" STREQUAL "DEBUG")
     set(LIB_SUFFIX "d${CMAKE_STATIC_LIBRARY_SUFFIX}")
   endif()
-  file(MAKE_DIRECTORY ${install_dir}/include)
-  set_target_properties(gtest PROPERTIES
-    IMPORTED_LOCATION ${install_dir}/lib/${LIB_PREFIX}gtest${LIB_SUFFIX}
-    INTERFACE_INCLUDE_DIRECTORIES ${install_dir}/include
-  )
-  set_target_properties(gtest_main PROPERTIES
-    IMPORTED_LOCATION ${install_dir}/lib/${LIB_PREFIX}gtest_main${LIB_SUFFIX}
-    INTERFACE_INCLUDE_DIRECTORIES ${install_dir}/include
-  )
-  add_dependencies(gtest googletest)
-  add_dependencies(gtest_main googletest)
-  set(GTEST_BOTH_LIBRARIES gtest gtest_main)
-  set(GTEST_INCLUDE_DIRS ${install_dir}/include)
+
+  # Use gmock_main instead of gtest_main because it initializes gtest as well.
+  # Note: The libraries are listed in reverse order of their dependancies.
+  foreach(LIB gtest gmock gmock_main)
+    add_library(${LIB} UNKNOWN IMPORTED)
+    set_target_properties(${LIB} PROPERTIES
+      IMPORTED_LOCATION ${install_dir}/lib/${LIB_PREFIX}${LIB}${LIB_SUFFIX}
+      INTERFACE_INCLUDE_DIRECTORIES ${GTEST_INCLUDE_DIRS}
+      INTERFACE_LINK_LIBRARIES "${GTEST_BOTH_LIBRARIES}"
+    )
+    add_dependencies(${LIB} googletest)
+    list(APPEND GTEST_BOTH_LIBRARIES ${LIB})
+  endforeach()
 endmacro(build_external_gtest)
 
 if (BENCHMARK_ENABLE_GTEST_TESTS)
   if (IS_DIRECTORY ${CMAKE_SOURCE_DIR}/googletest)
+    set(GTEST_ROOT "${CMAKE_SOURCE_DIR}/googletest")
     set(INSTALL_GTEST OFF CACHE INTERNAL "")
     set(INSTALL_GMOCK OFF CACHE INTERNAL "")
     add_subdirectory(${CMAKE_SOURCE_DIR}/googletest)
-    set(GTEST_BOTH_LIBRARIES gtest gtest_main)
+    set(GTEST_BOTH_LIBRARIES gtest gmock gmock_main)
+    foreach(HEADER test mock)
+      # CMake 2.8 and older don't respect INTERFACE_INCLUDE_DIRECTORIES, so we
+      # have to add the paths ourselves.
+      set(HFILE g${HEADER}/g${HEADER}.h)
+      set(HPATH ${GTEST_ROOT}/google${HEADER}/include)
+      find_path(HEADER_PATH_${HEADER} ${HFILE}
+          NO_DEFAULT_PATHS
+          HINTS ${HPATH}
+      )
+      if (NOT HEADER_PATH_${HEADER})
+        message(FATAL "Failed to find header ${HFILE} in ${HPATH}")
+      endif()
+      list(APPEND GTEST_INCLUDE_DIRS ${HEADER_PATH_${HEADER}})
+    endforeach()
   elseif(BENCHMARK_DOWNLOAD_DEPENDENCIES)
     build_external_gtest()
   else()
     find_package(GTest REQUIRED)
+    find_path(GMOCK_INCLUDE_DIRS gmock/gmock.h
+        HINTS ${GTEST_INCLUDE_DIRS})
+    if (NOT GMOCK_INCLUDE_DIRS)
+      message(FATAL "Failed to find header gmock/gmock.h with hint ${GTEST_INCLUDE_DIRS}")
+    endif()
+    set(GTEST_INCLUDE_DIRS ${GTEST_INCLUDE_DIRS} ${GMOCK_INCLUDE_DIRS})
+    # FIXME: We don't currently require the gmock library to build the tests,
+    # and it's likely we won't find it, so we don't try. As long as we've
+    # found the gmock/gmock.h header and gtest_main that should be good enough.
   endif()
 endif()