llext-edk: (refact) filter flags in post-processing step

This changes the LLEXT EDK flag filtering to be done after the main
Zephyr build is completed. Instead of filtering the flags via genexes,
the full set is passed to the script along with the set of filters to be
applied, and the filter is applied later.

No functional change is intended.

Signed-off-by: Luca Burelli <[email protected]>

Author: pillo79

CMakeLists.txt

@@ -2292,18 +2292,14 @@ if(CONFIG_LLEXT_EDK)
   zephyr_get_compile_definitions_for_lang(C zephyr_defs)
   zephyr_get_compile_options_for_lang(C zephyr_flags)
 
-  # Filter out non LLEXT and LLEXT_EDK flags - and add required ones
-  llext_filter_zephyr_flags(LLEXT_REMOVE_FLAGS ${zephyr_flags} llext_filt_flags)
-  llext_filter_zephyr_flags(LLEXT_EDK_REMOVE_FLAGS ${llext_filt_flags} llext_filt_flags)
-
-  set(llext_edk_cflags ${zephyr_defs} -DLL_EXTENSION_BUILD)
-  list(APPEND llext_edk_cflags ${llext_filt_flags})
-  list(APPEND llext_edk_cflags ${LLEXT_APPEND_FLAGS})
-  list(APPEND llext_edk_cflags ${LLEXT_EDK_APPEND_FLAGS})
+  set(llext_edk_cflags ${zephyr_defs} ${zephyr_flags})
 
+  # Export current settings for use in LLEXT EDK generation
   build_info(llext-edk file PATH ${llext_edk_file})
   build_info(llext-edk cflags VALUE ${llext_edk_cflags})
   build_info(llext-edk include-dirs VALUE "$<TARGET_PROPERTY:zephyr_interface,INTERFACE_INCLUDE_DIRECTORIES>")
+  build_info(llext-edk remove-cflags VALUE ${LLEXT_REMOVE_FLAGS} ${LLEXT_EDK_REMOVE_FLAGS})
+  build_info(llext-edk append-cflags VALUE ${LLEXT_APPEND_FLAGS} ${LLEXT_EDK_APPEND_FLAGS} -DLL_EXTENSION_BUILD)
 
   add_custom_command(
     OUTPUT ${llext_edk_file}

cmake/llext-edk.cmake

@@ -156,6 +156,13 @@ set(build_info_file ${PROJECT_BINARY_DIR}/../build_info.yml)
 yaml_load(FILE ${build_info_file} NAME build_info)
 
 yaml_get(llext_edk_cflags NAME build_info KEY cmake llext-edk cflags)
+yaml_get(llext_remove_cflags NAME build_info KEY cmake llext-edk remove-cflags)
+yaml_get(llext_append_cflags NAME build_info KEY cmake llext-edk append-cflags)
+foreach(item IN_LIST ${llext_remove_cflags})
+  list(FILTER llext_edk_cflags EXCLUDE REGEX "^${item}$")
+endforeach()
+list(APPEND llext_edk_cflags ${llext_append_cflags})
+
 yaml_get(llext_edk_file NAME build_info KEY cmake llext-edk file)
 yaml_get(INTERFACE_INCLUDE_DIRECTORIES NAME build_info KEY cmake llext-edk include-dirs)
 yaml_get(APPLICATION_SOURCE_DIR NAME build_info KEY cmake application source-dir)

scripts/schemas/build-schema.yml

@@ -95,6 +95,14 @@ mapping:
             type: seq
             sequence:
               - type: str
+          remove-cflags:
+            type: seq
+            sequence:
+              - type: str
+          append-cflags:
+            type: seq
+            sequence:
+              - type: str
       sysbuild:
         type: bool
       toolchain: