From: Jose Luis Rivero <jrivero@osrfoundation.org>
Date: Tue, 14 Apr 2020 16:31:14 +0200
Subject: Use system packaged gtest

Last-Update: 2016-10-26
---
 cmake/FindGtest.cmake   | 40 ++++++++++++++++++++++++++++++++++++++++
 cmake/GazeboUtils.cmake |  1 -
 test/CMakeLists.txt     | 13 ++++++++-----
 3 files changed, 48 insertions(+), 6 deletions(-)
 create mode 100644 cmake/FindGtest.cmake

diff --git a/cmake/FindGtest.cmake b/cmake/FindGtest.cmake
new file mode 100644
index 0000000..a154a2c
--- /dev/null
+++ b/cmake/FindGtest.cmake
@@ -0,0 +1,40 @@
+###############################################################################
+# Find GTest
+#
+# This sets the following variables:
+# GTEST_FOUND - True if GTest was found.
+# GTEST_INCLUDE_DIRS - Directories containing the GTest include files.
+# GTEST_SRC - Directories containing the GTest source files.
+
+if(CMAKE_SYSTEM_NAME STREQUAL Linux)
+    set(CMAKE_INCLUDE_PATH ${CMAKE_INCLUDE_PATH} /usr /usr/local)
+endif(CMAKE_SYSTEM_NAME STREQUAL Linux)
+if(APPLE)
+  list(APPEND CMAKE_INCLUDE_PATH /opt/local)
+  set(CMAKE_FIND_FRAMEWORK NEVER)
+endif()
+
+find_path(GTEST_INCLUDE_DIR gtest/gtest.h
+    HINTS "${GTEST_ROOT}" "$ENV{GTEST_ROOT}"
+    PATHS "$ENV{PROGRAMFILES}/gtest" "$ENV{PROGRAMW6432}/gtest"
+    PATHS "$ENV{PROGRAMFILES}/gtest-1.7.0" "$ENV{PROGRAMW6432}/gtest-1.7.0"
+    PATH_SUFFIXES gtest include/gtest include)
+
+find_path(GTEST_SRC_DIR src/gtest-all.cc
+    HINTS "${GTEST_ROOT}" "$ENV{GTEST_ROOT}"
+    PATHS "$ENV{PROGRAMFILES}/gtest" "$ENV{PROGRAMW6432}/gtest"
+    PATHS "$ENV{PROGRAMFILES}/gtest-1.7.0" "$ENV{PROGRAMW6432}/gtest-1.7.0"
+    PATH /usr/src/gtest
+    PATH_SUFFIXES gtest src/gtest)
+
+set(GTEST_INCLUDE_DIRS ${GTEST_INCLUDE_DIR})
+set(CMAKE_FIND_FRAMEWORK)
+
+include(FindPackageHandleStandardArgs)
+find_package_handle_standard_args(Gtest DEFAULT_MSG GTEST_INCLUDE_DIR GTEST_SRC_DIR)
+
+mark_as_advanced(GTEST_INCLUDE_DIR GTEST_SRC_DIR)
+
+if(GTEST_FOUND)
+  message(STATUS "GTest found (include: ${GTEST_INCLUDE_DIRS}, src: ${GTEST_SRC_DIR})")
+endif(GTEST_FOUND)
diff --git a/cmake/GazeboUtils.cmake b/cmake/GazeboUtils.cmake
index 15138fe..c192fa6 100644
--- a/cmake/GazeboUtils.cmake
+++ b/cmake/GazeboUtils.cmake
@@ -203,7 +203,6 @@ endmacro()
 # This should be migrated to more fine control solution based on set_property APPEND
 # directories. It's present on cmake 2.8.8 while precise version is 2.8.7
 link_directories(${PROJECT_BINARY_DIR}/test)
-include_directories("${PROJECT_SOURCE_DIR}/test/gtest/include")
 include (${gazebo_cmake_dir}/GazeboTestUtils.cmake)
 
 #################################################
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 975bed1..3331607 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -1,12 +1,13 @@
+include (${gazebo_cmake_dir}/FindGtest.cmake)
+
 include_directories (
   ${ODE_INCLUDE_DIRS}
   ${OPENGL_INCLUDE_DIR}
   ${OGRE_INCLUDE_DIRS}
   ${SDFormat_INCLUDE_DIRS}
   ${Boost_INCLUDE_DIRS}
-  ${PROJECT_SOURCE_DIR}/test/gtest/include
-  ${PROJECT_SOURCE_DIR}/test/gtest
-  ${PROJECT_SOURCE_DIR}/test
+  ${GTEST_INCLUDE_DIRS}/gtest/
+  ${GTEST_SRC_DIR}
 )
 
 link_directories(
@@ -24,8 +25,8 @@ endif()
 configure_file (test_config.h.in ${PROJECT_BINARY_DIR}/test_config.h)
 
 # Build gtest
-add_library(gtest STATIC gtest/src/gtest-all.cc)
-add_library(gtest_main STATIC gtest/src/gtest_main.cc)
+add_library(gtest STATIC ${GTEST_SRC_DIR}/src/gtest-all.cc)
+add_library(gtest_main STATIC ${GTEST_SRC_DIR}/src/gtest_main.cc)
 target_link_libraries(gtest_main gtest)
 set(GTEST_LIBRARY "${PROJECT_BINARY_DIR}/test/libgtest.a")
 set(GTEST_MAIN_LIBRARY "${PROJECT_BINARY_DIR}/test/libgtest_main.a")
@@ -34,6 +35,8 @@ execute_process(COMMAND cmake -E remove_directory ${CMAKE_BINARY_DIR}/test_resul
 execute_process(COMMAND cmake -E make_directory ${CMAKE_BINARY_DIR}/test_results)
 include_directories(${GTEST_INCLUDE_DIRS})
 
+include_directories(${PROJECT_SOURCE_DIR}/test)
+
 add_subdirectory(plugins)
 
 set(TEST_TYPE "PERFORMANCE")