cmake: fix find_and_handle_library and move it to external file cmake/LeptonicaFunc.cmake

CMakeLists.txt

@@ -74,27 +74,13 @@ set(leptonica_INSTALL_CMAKE_DIR
     "lib/cmake/leptonica"
     CACHE STRING "Install destination for CMake package files")
 
+include(LeptonicaFunc)
+
 if(NOT SW_BUILD)
   find_package(PkgConfig QUIET)
   set(pkgs_private "")
   set(libs_private "")
 
-  function(find_and_handle_library LIB_NAME ENABLE_OPTION PKG_CONFIG_NAME)
-    if(${ENABLE_OPTION})
-      find_package(${PKG_CONFIG_NAME})
-      if(${PKG_CONFIG_NAME}_FOUND)
-        set(pkgs_private "${pkgs_private} ${PKG_CONFIG_NAME}")
-      else()
-        if(STRICT_CONF)
-          message(
-            FATAL_ERROR
-              "Could not find ${PKG_CONFIG_NAME} libs. Use -D${ENABLE_OPTION}=OFF to disable ${PKG_CONFIG_NAME} support."
-          )
-        endif()
-      endif()
-    endif()
-  endfunction()
-
   find_and_handle_library(ZLIB ENABLE_ZLIB ZLIB)
   find_and_handle_library(PNG ENABLE_PNG PNG)
   find_and_handle_library(JPEG ENABLE_JPEG JPEG)

cmake/LeptonicaFunc.cmake

@@ -0,0 +1,36 @@
+# cmake/LeptonicaFunc.cmake
+
+# ##############################################################################
+# FUNCTION find_and_handle_library
+# ##############################################################################
+function(find_and_handle_library LIB_NAME ENABLE_OPTION PKG_CONFIG_NAME)
+  if(${ENABLE_OPTION})
+    find_package(${PKG_CONFIG_NAME})
+    if(${PKG_CONFIG_NAME}_FOUND)
+      set(pkgs_private
+          "${pkgs_private} ${PKG_CONFIG_NAME}"
+          PARENT_SCOPE)
+      # Propagate found variables to parent scope
+      set(${PKG_CONFIG_NAME}_FOUND
+          ${${PKG_CONFIG_NAME}_FOUND}
+          PARENT_SCOPE)
+      if(DEFINED ${PKG_CONFIG_NAME}_LIBRARIES)
+        set(${PKG_CONFIG_NAME}_LIBRARIES
+            ${${PKG_CONFIG_NAME}_LIBRARIES}
+            PARENT_SCOPE)
+      endif()
+      if(DEFINED ${PKG_CONFIG_NAME}_INCLUDE_DIRS)
+        set(${PKG_CONFIG_NAME}_INCLUDE_DIRS
+            ${${PKG_CONFIG_NAME}_INCLUDE_DIRS}
+            PARENT_SCOPE)
+      endif()
+    else()
+      if(STRICT_CONF)
+        message(
+          FATAL_ERROR
+            "Could not find ${PKG_CONFIG_NAME} libs. Use -D${ENABLE_OPTION}=OFF to disable ${PKG_CONFIG_NAME} support."
+        )
+      endif()
+    endif()
+  endif()
+endfunction()