Redesign safeguard_properties() to be a macro instead of a function

Author: aedart

cmake/rsp/helpers.cmake

@@ -90,45 +90,28 @@ if (NOT COMMAND "safeguard_properties")
 
     #! safeguard_properties : Invoke a "risky" callback whilst "safeguarding" properties
     #
-    # Function copies the values of the specified properties, invokes the callback, and
-    # restores the properties' values.
+    # Macro copies the values of the specified properties, invokes the callback, and
+    # restores the properties' original values.
     #
-    # Caution: This function does NOT prevent properties from being force-cached.
+    # Caution: This macro does NOT prevent properties from being force-cached.
     # Environment variables are NOT prevented changed.
     #
-    # Alternatively, consider using cmake's `block()`.
+    # Alternatively, consider using cmake's `block()` or a function with its own variable
+    # scope.
     #
     # @see https://cmake.org/cmake/help/latest/manual/cmake-language.7.html#variables
     # @see https://cmake.org/cmake/help/latest/manual/cmake-language.7.html#environment-variables
     # @see https://cmake.org/cmake/help/latest/command/block.html#block
     #
-    # @param [CALLBACK <command>]           Risky command or macro to be invoked.
-    # @param [PROPERTIES <variable>...]     One or more properties to safeguard.
+    # @param <command> callback     Risky command or macro to be invoked.
+    # @param <list> properties      List of variable names - variables to safeguard from
+    #                               undesired value changes.
     #
-    # @return
-    #       [PROPERTIES <variable>...]      Restored properties
-    #
-    function(safeguard_properties)
-        set(options "") # N/A
-        set(oneValueArgs CALLBACK)
-        set(multiValueArgs PROPERTIES)
-
-        cmake_parse_arguments(INPUT "${options}" "${oneValueArgs}" "${multiValueArgs}" ${ARGN})
-        requires_arguments("CALLBACK;PROPERTIES" INPUT)
-
-        # ---------------------------------------------------------------------------------------------- #
-
-        # Abort if callback not defined
-        if (NOT COMMAND "${INPUT_CALLBACK}")
-            message(FATAL_ERROR "Callback \"${INPUT_CALLBACK}()\" does not exist")
-        endif ()
-
-        # ---------------------------------------------------------------------------------------------- #
-
+    macro(safeguard_properties callback properties)
         set(prefix "original_")
 
         # Copy each provided property
-        foreach (prop ${INPUT_PROPERTIES})
+        foreach (prop ${properties})
             message(VERBOSE "Safeguarding: ${prop}, original value: ${${prop}}")
 
             set("${prefix}${prop}" "${${prop}}")
@@ -137,17 +120,17 @@ if (NOT COMMAND "safeguard_properties")
         # ---------------------------------------------------------------------------------------------- #
 
         # Invoke the risky callback
-        message(VERBOSE "Invoking risky callback: ${INPUT_CALLBACK}")
-        cmake_language(CALL "${INPUT_CALLBACK}")
+        message(VERBOSE "Invoking risky callback: ${callback}")
+        cmake_language(CALL "${callback}")
 
         # ---------------------------------------------------------------------------------------------- #
 
         # Restore each provided property
-        foreach (prop ${INPUT_PROPERTIES})
+        foreach (prop ${properties})
             message(VERBOSE "Restoring: ${prop} from: ${${prop}}, to original value: ${${prefix}${prop}}")
 
-            # Ensure that property is set on parent scope
-            set("${prop}" "${${prefix}${prop}}" PARENT_SCOPE)
+            # Restore property's original value
+            set("${prop}" "${${prefix}${prop}}")
         endforeach ()
-    endfunction()
+    endmacro()
 endif ()