From c6d8892e5d1bac2803b53063fe3e3c23efe46574 Mon Sep 17 00:00:00 2001
From: Niels Lohmann <mail@nlohmann.me>
Date: Sun, 6 Mar 2022 15:33:05 +0100
Subject: [PATCH] FetchContent_MakeAvailable (#3351)

* :wrench: use FetchContent_MakeAvailable

* :green_heart: fix test names
---
 README.md                                     | 11 ++--------
 doc/mkdocs/docs/integration/cmake.md          | 11 ++--------
 test/CMakeLists.txt                           |  1 +
 test/cmake_fetch_content2/CMakeLists.txt      | 20 +++++++++++++++++++
 .../project/CMakeLists.txt                    | 15 ++++++++++++++
 test/cmake_fetch_content2/project/main.cpp    |  8 ++++++++
 6 files changed, 48 insertions(+), 18 deletions(-)
 create mode 100644 test/cmake_fetch_content2/CMakeLists.txt
 create mode 100644 test/cmake_fetch_content2/project/CMakeLists.txt
 create mode 100644 test/cmake_fetch_content2/project/main.cpp

diff --git a/README.md b/README.md
index 89676cf371..c6babb64ed 100644
--- a/README.md
+++ b/README.md
@@ -1191,15 +1191,8 @@ Example:
 ```cmake
 include(FetchContent)
 
-FetchContent_Declare(json
-  URL https://github.com/nlohmann/json/releases/download/v3.10.5/json.tar.xz
-)
-
-FetchContent_GetProperties(json)
-if(NOT json_POPULATED)
-  FetchContent_Populate(json)
-  add_subdirectory(${json_SOURCE_DIR} ${json_BINARY_DIR} EXCLUDE_FROM_ALL)
-endif()
+FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.10.5/json.tar.xz)
+FetchContent_MakeAvailable(json)
 
 target_link_libraries(foo PRIVATE nlohmann_json::nlohmann_json)
 ```
diff --git a/doc/mkdocs/docs/integration/cmake.md b/doc/mkdocs/docs/integration/cmake.md
index dbb8c2d660..2247ba0097 100644
--- a/doc/mkdocs/docs/integration/cmake.md
+++ b/doc/mkdocs/docs/integration/cmake.md
@@ -100,15 +100,8 @@ automatically download a release as a dependency at configure type.
 
     include(FetchContent)
     
-    FetchContent_Declare(json
-        URL https://github.com/nlohmann/json/releases/download/v3.10.5/json.tar.xz
-    )
-    
-    FetchContent_GetProperties(json)
-    if(NOT json_POPULATED)
-        FetchContent_Populate(json)
-        add_subdirectory(${json_SOURCE_DIR} ${json_BINARY_DIR} EXCLUDE_FROM_ALL)
-    endif()
+    FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.10.5/json.tar.xz)
+    FetchContent_MakeAvailable(json)
     
     add_executable(example example.cpp)
     target_link_libraries(example PRIVATE nlohmann_json::nlohmann_json)
diff --git a/test/CMakeLists.txt b/test/CMakeLists.txt
index 4c741f2743..c296621349 100644
--- a/test/CMakeLists.txt
+++ b/test/CMakeLists.txt
@@ -170,4 +170,5 @@ endif()
 
 add_subdirectory(cmake_add_subdirectory)
 add_subdirectory(cmake_fetch_content)
+add_subdirectory(cmake_fetch_content2)
 add_subdirectory(cmake_target_include_directories)
diff --git a/test/cmake_fetch_content2/CMakeLists.txt b/test/cmake_fetch_content2/CMakeLists.txt
new file mode 100644
index 0000000000..40e75e832e
--- /dev/null
+++ b/test/cmake_fetch_content2/CMakeLists.txt
@@ -0,0 +1,20 @@
+if (${CMAKE_VERSION} VERSION_GREATER "3.14.0")
+  add_test(NAME cmake_fetch_content2_configure
+    COMMAND ${CMAKE_COMMAND}
+    -G "${CMAKE_GENERATOR}"
+    -DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}
+    -Dnlohmann_json_source=${PROJECT_SOURCE_DIR}
+    ${CMAKE_CURRENT_SOURCE_DIR}/project
+  )
+  add_test(NAME cmake_fetch_content2_build
+    COMMAND ${CMAKE_COMMAND} --build .
+  )
+  set_tests_properties(cmake_fetch_content2_configure PROPERTIES
+    FIXTURES_SETUP cmake_fetch_content2
+    LABELS "git_required;not_reproducible"
+  )
+  set_tests_properties(cmake_fetch_content2_build PROPERTIES
+    FIXTURES_REQUIRED cmake_fetch_content2
+    LABELS "git_required;not_reproducible"
+  )
+endif()
diff --git a/test/cmake_fetch_content2/project/CMakeLists.txt b/test/cmake_fetch_content2/project/CMakeLists.txt
new file mode 100644
index 0000000000..734b9cc0ed
--- /dev/null
+++ b/test/cmake_fetch_content2/project/CMakeLists.txt
@@ -0,0 +1,15 @@
+cmake_minimum_required(VERSION 3.14)
+
+project(DummyImport CXX)
+
+include(FetchContent)
+
+get_filename_component(GIT_REPOSITORY_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}/../../.. ABSOLUTE)
+FetchContent_Declare(json GIT_REPOSITORY ${GIT_REPOSITORY_DIRECTORY} GIT_TAG HEAD)
+FetchContent_MakeAvailable(json)
+
+add_executable(with_namespace_target main.cpp)
+target_link_libraries(with_namespace_target nlohmann_json::nlohmann_json)
+
+add_executable(without_namespace_target main.cpp)
+target_link_libraries(without_namespace_target nlohmann_json)
diff --git a/test/cmake_fetch_content2/project/main.cpp b/test/cmake_fetch_content2/project/main.cpp
new file mode 100644
index 0000000000..d2d118b854
--- /dev/null
+++ b/test/cmake_fetch_content2/project/main.cpp
@@ -0,0 +1,8 @@
+#include <nlohmann/json.hpp>
+
+int main(int argc, char **argv)
+{
+    nlohmann::json j;
+
+    return 0;
+}