From 6b9bead140676fa04d790a6d5e4625a2efb0cb27 Mon Sep 17 00:00:00 2001
From: Nicolas Morales <nmmoral@sandia.gov>
Date: Fri, 14 Feb 2025 09:23:28 +0100
Subject: [PATCH 1/3] cmake: remove manual download for googletest and use
 fetchcontent instead

---
 cmake/googletest/CMakeLists.txt.in | 16 --------------
 tests/CMakeLists.txt               | 34 +++++++-----------------------
 2 files changed, 8 insertions(+), 42 deletions(-)
 delete mode 100644 cmake/googletest/CMakeLists.txt.in

diff --git a/cmake/googletest/CMakeLists.txt.in b/cmake/googletest/CMakeLists.txt.in
deleted file mode 100644
index b25167b4..00000000
--- a/cmake/googletest/CMakeLists.txt.in
+++ /dev/null
@@ -1,16 +0,0 @@
-# from https://github.com/google/googletest/blob/master/googletest/README.md
-cmake_minimum_required(VERSION 3.5)
-
-project(googletest-download NONE)
-
-include(ExternalProject)
-ExternalProject_Add(googletest
-  GIT_REPOSITORY    https://github.com/google/googletest.git
-  GIT_TAG           main
-  SOURCE_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-src"
-  BINARY_DIR        "${CMAKE_CURRENT_BINARY_DIR}/googletest-build"
-  CONFIGURE_COMMAND ""
-  BUILD_COMMAND     ""
-  INSTALL_COMMAND   ""
-  TEST_COMMAND      ""
-)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 14d61b2f..672d93cb 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -33,33 +33,15 @@ if(MDSPAN_USE_SYSTEM_GTEST)
   find_package(GTest CONFIG REQUIRED)
   add_library(gtest_main ALIAS GTest::gtest_main)
 else()
-  # adapted from https://github.com/google/googletest/blob/master/googletest/README.md
-  configure_file(${PROJECT_SOURCE_DIR}/cmake/googletest/CMakeLists.txt.in googletest-download/CMakeLists.txt)
-  execute_process(COMMAND ${CMAKE_COMMAND} -G "${CMAKE_GENERATOR}" .
-    RESULT_VARIABLE result
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download
-  )
-  if(result)
-    message(FATAL_ERROR "CMake step for googletest failed: ${result}")
-  endif()
-  execute_process(COMMAND ${CMAKE_COMMAND} --build .
-    RESULT_VARIABLE result
-    WORKING_DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/googletest-download
-  )
-  if(result)
-    message(FATAL_ERROR "Build step for googletest failed: ${result}")
-  endif()
-
-  # Prevent overriding the parent project's compiler/linker
-  # settings on Windows
-  set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
-
-  # Add googletest directly to our build. This defines
-  # the gtest and gtest_main targets.
-  add_subdirectory(${CMAKE_CURRENT_BINARY_DIR}/googletest-src
-    ${CMAKE_CURRENT_BINARY_DIR}/googletest-build
-    EXCLUDE_FROM_ALL
+  include(FetchContent)
+  
+  fetchcontent_declare(
+      googletest
+      GIT_REPOSITORY https://github.com/google/googletest.git
+      GIT_TAG v1.16.0
   )
+  
+  fetchcontent_makeavailable(googletest)
 endif()
 
 # FIXME_MSVC

From 920f2b9ab7b823cf68a388a438e283f0f0fe61cd Mon Sep 17 00:00:00 2001
From: Nicolas Morales <nmmoral@sandia.gov>
Date: Fri, 14 Feb 2025 09:53:06 +0100
Subject: [PATCH 2/3] cmake: when linking googletest switch alias to
 fetchcontent side so that we use the namespaced target (and potentially avoid
 adding -lgtest_main to the command line)

---
 tests/CMakeLists.txt | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index 672d93cb..d10caa3a 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -20,7 +20,7 @@ function(mdspan_add_test name)
     set_source_files_properties(${name} PROPERTIES LANGUAGE ${MDSPAN_TEST_LANGUAGE})
   endif()
   add_executable(${name} ${ARGUMENT_SOURCE})
-  target_link_libraries(${name} mdspan gtest_main)
+  target_link_libraries(${name} mdspan GTest::gtest_main)
   add_test(${name} ${name})
   set_property(TARGET ${name} PROPERTY COMPILE_WARNING_AS_ERROR ON)
   target_compile_definitions(${name}
@@ -31,7 +31,6 @@ endfunction()
 
 if(MDSPAN_USE_SYSTEM_GTEST)
   find_package(GTest CONFIG REQUIRED)
-  add_library(gtest_main ALIAS GTest::gtest_main)
 else()
   include(FetchContent)
   
@@ -42,6 +41,8 @@ else()
   )
   
   fetchcontent_makeavailable(googletest)
+  
+  add_library(GTest::gtest_main ALIAS gtest_main)
 endif()
 
 # FIXME_MSVC

From 03361cf3b2308ce98f5d570cd58375f218fef2bc Mon Sep 17 00:00:00 2001
From: Nicolas Morales <nmmoral@sandia.gov>
Date: Fri, 14 Feb 2025 11:34:53 +0100
Subject: [PATCH 3/3] cmake: fix crt library on windows

---
 tests/CMakeLists.txt | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d10caa3a..201dac49 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -34,6 +34,9 @@ if(MDSPAN_USE_SYSTEM_GTEST)
 else()
   include(FetchContent)
   
+  if (MSVC)
+    set(gtest_force_shared_crt ON CACHE BOOL "" FORCE)
+  endif()
   fetchcontent_declare(
       googletest
       GIT_REPOSITORY https://github.com/google/googletest.git