Merge pull request #119 from nim65s/devel

CMake: allow use of installed jrl-cmakemodule

CMakeLists.txt

@@ -19,14 +19,33 @@ set(CXX_DISABLE_WERROR TRUE)
 
 # JRL-cmakemodule setup
 set(JRL_CMAKE_MODULES "${CMAKE_CURRENT_LIST_DIR}/cmake")
-if(NOT EXISTS "${CMAKE_SOURCE_DIR}/cmake/base.cmake")
-  message(STATUS "JRL cmakemodules not found. Let's fetch it.")
-  include(FetchContent)
-  FetchContent_Declare(
-    "jrl-cmakemodules"
-    GIT_REPOSITORY "https://github.com/jrl-umi3218/jrl-cmakemodules.git")
-  FetchContent_MakeAvailable("jrl-cmakemodules")
-  FetchContent_GetProperties("jrl-cmakemodules" SOURCE_DIR JRL_CMAKE_MODULES)
+if(EXISTS "${JRL_CMAKE_MODULES}/base.cmake")
+  message(STATUS "JRL cmakemodules found in 'cmake/' git submodule")
+else()
+  find_package(jrl-cmakemodules QUIET CONFIG)
+  if(jrl-cmakemodules_FOUND)
+    get_property(
+      JRL_CMAKE_MODULES
+      TARGET jrl-cmakemodules::jrl-cmakemodules
+      PROPERTY INTERFACE_INCLUDE_DIRECTORIES)
+    message(STATUS "JRL cmakemodules found on system at ${JRL_CMAKE_MODULES}")
+  elseif(${CMAKE_VERSION} VERSION_LESS "3.14.0")
+    message(
+      FATAL_ERROR
+        "\nCan't find jrl-cmakemodules. Please either:\n"
+        "  - use git submodule: 'git submodule update --init'\n"
+        "  - or install https://github.com/jrl-umi3218/jrl-cmakemodules\n"
+        "  - or upgrade your CMake version to >= 3.14 to allow automatic fetching\n"
+    )
+  else()
+    message(STATUS "JRL cmakemodules not found. Let's fetch it.")
+    include(FetchContent)
+    FetchContent_Declare(
+      "jrl-cmakemodules"
+      GIT_REPOSITORY "https://github.com/jrl-umi3218/jrl-cmakemodules.git")
+    FetchContent_MakeAvailable("jrl-cmakemodules")
+    FetchContent_GetProperties("jrl-cmakemodules" SOURCE_DIR JRL_CMAKE_MODULES)
+  endif()
 endif()
 
 include("${JRL_CMAKE_MODULES}/base.cmake")