Add initial third party library support with the google test framework

CMakeLists.txt

@@ -4,7 +4,7 @@
 #------------------------------------------------------------------------------#
 
 cmake_minimum_required(VERSION 3.7)
-project(ADIOS VERSION 2.0.a)
+project(ADIOS VERSION 2.0.0)
 
 #------------------------------------------------------------------------------#
 # Some boilerplate to setup nice output directories
@@ -50,11 +50,24 @@ if(ADIOS_ENABLE_PIC)
   set(CMAKE_POSITION_INDEPENDENT_CODE ON)
 endif()
 
+#------------------------------------------------------------------------------#
+# Third party libraries
+#------------------------------------------------------------------------------#
+include(CTest)
+add_subdirectory(thirdparty)
+
 #------------------------------------------------------------------------------#
 # Main library source
 #------------------------------------------------------------------------------#
 add_subdirectory(source)
 
+#------------------------------------------------------------------------------#
+# Installation
+#------------------------------------------------------------------------------#
+install(DIRECTORY include/
+  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
+  FILES_MATCHING PATTERN "*.h"
+)
 #------------------------------------------------------------------------------#
 # Examples
 #------------------------------------------------------------------------------#
@@ -66,20 +79,8 @@ endif()
 #------------------------------------------------------------------------------#
 # Testing
 #------------------------------------------------------------------------------#
-include(CTest)
-option(ADIOS_ENABLE_TESTING "Enable ADIOS Testing" ON)
-set(ENABLE_TESTING ${ADIOS_ENABLE_TESTING} CACHE INTERNAL "" FORCE)
-mark_as_advanced(ENABLE_TESTING)
-if(ADIOS_ENABLE_TESTING)
+# We have to wait until after the library is defined to enable testing
+if(BUILD_TESTING)
   enable_testing()
   add_subdirectory(testing)
 endif()
-
-#------------------------------------------------------------------------------#
-# Installation
-#------------------------------------------------------------------------------#
-install(DIRECTORY include/
-  DESTINATION ${CMAKE_INSTALL_INCLUDEDIR}
-  FILES_MATCHING PATTERN "*.h"
-)
-

thirdparty/CMakeLists.txt

@@ -0,0 +1,28 @@
+set(ADIOS_THIRDPARTY_DOWNLOAD_DIR ${CMAKE_CURRENT_BINARY_DIR}/downloads
+  CACHE PATH "Download directory for third party dependencies")
+
+include(ExternalProject)
+
+# Boilerplate settings for a common external project infrastructure
+set(EP_ARGS
+  DOWNLOAD_DIR ${ADIOS_THIRDPARTY_DOWNLOAD_DIR}
+  PREFIX       .
+  SOURCE_DIR   source
+  BINARY_DIR   build
+  STAMP_DIR    stamp
+  INSTALL_DIR  install)
+
+# Use Google Test for a unit testing framework
+cmake_dependent_option(ADIOS_USE_SYSTEM_GOOGLETEST
+  "Use a system-supplied Google Test framework" OFF
+  "BUILD_TESTING" OFF)
+if(BUILD_TESTING)
+  if(NOT ADIOS_USE_SYSTEM_GOOGLETEST)
+    add_subdirectory(googletest)
+  endif()
+  find_package(GTest REQUIRED)
+  if(NOT ADIOS_USE_SYSTEM_GOOGLETEST)
+    add_dependencies(GTest::GTest googletest)
+    add_dependencies(GTest::Main googletest)
+  endif()
+endif()

thirdparty/googletest/CMakeLists.txt

@@ -0,0 +1,36 @@
+
+ExternalProject_Add(googletest
+  URL     https://github.com/google/googletest/archive/release-1.8.0.zip
+  URL_MD5 adfafc8512ab65fd3cf7955ef0100ff5
+  ${EP_ARGS}
+  CMAKE_ARGS
+    -DCMAKE_INSTALL_PREFIX=${CMAKE_CURRENT_BINARY_DIR}/install
+    -DCMAKE_POLICY_DEFAULT_CMP0048=OLD
+    -DCMAKE_POLICY_DEFAULT_CMP0063=NEW
+    -DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
+    -DBUILD_SHARED_LIBS=${BUILD_SHARED_LIBS}
+    -DBUILD_GMOCK=OFF
+    -DBUILD_GTEST=ON
+    -Dgtest_build_samples=OFF
+    -Dgtest_build_tests=OFF
+    -Dgtest_hide_internal_symbols=ON
+    -Dgtest_disable_pthreads=OFF
+    -Dgtest_force_shared_crt=OFF)
+
+function(get_libfile var name)
+  if(BUILD_SHARED_LIBS)
+    set(${var} ${CMAKE_SHARED_LIBRARY_PREFIX}${name}${CMAKE_SHARED_LIBRARY_SUFFIX} PARENT_SCOPE)
+  else()
+    set(${var} ${CMAKE_STATIC_LIBRARY_PREFIX}${name}${CMAKE_STATIC_LIBRARY_SUFFIX} PARENT_SCOPE)
+  endif()
+endfunction()
+
+get_libfile(GTEST_LIBRARY gtest)
+get_libfile(GTEST_MAIN_LIBRARY gtest_main)
+set(GTEST_ROOT ${CMAKE_CURRENT_BINARY_DIR}/install)
+set(GTEST_INCLUDE_DIR ${GTEST_ROOT}/include
+  CACHE PATH "")
+set(GTEST_LIBRARY ${GTEST_ROOT}/lib/${GTEST_LIBRARY}
+  CACHE FILEPATH "")
+set(GTEST_MAIN_LIBRARY ${GTEST_ROOT}/lib/${GTEST_MAIN_LIBRARY}
+  CACHE FILEPATH "")