Fixed aliasing an imported target on CMake versions older than 3.18.

Author: dbs4261

CMakeLists.txt

@@ -241,6 +241,15 @@ endif()
 find_package(SQLite3 3.11 REQUIRED)
 
 if(NOT TARGET SQLite3::SQLite3) # CMake < 4.3
+  # Remove after CMake version bump to 3.18+
+  get_target_property(IS_SQLITE3_IMPORTED SQLite::SQLite3 IMPORTED)
+  if(IS_SQLITE3_IMPORTED AND CMAKE_VERSION VERSION_LESS "3.18")
+    set_target_properties(SQLite::SQLite3 PROPERTIES IMPORTED_GLOBAL TRUE)
+    message(DEPRECATION "If your project consumes PROJ as a subdirectory \
+      and also uses either the SQLite3::SQLite3 or SQLite::SQLite3 target, \
+      make sure you have your own call to find_package.\nThese targets \
+      will no longer be available to the global CMake scope once PROJ bumps to CMake v3.18+.")
+  endif()
   add_library(SQLite3::SQLite3 ALIAS SQLite::SQLite3)
 endif()