llext-edk: rework, read data from build_info.yml and .config

CMakeLists.txt

@@ -1990,7 +1990,6 @@ if (CONFIG_LLEXT AND CONFIG_LLEXT_EXPORT_BUILTINS_BY_SLID)
     --elf-file ${PROJECT_BINARY_DIR}/${KERNEL_ELF_NAME}
     --slid-listing ${PROJECT_BINARY_DIR}/slid_listing.txt
   )
-
 endif()
 
 if(NOT CMAKE_C_COMPILER_ID STREQUAL "ARMClang")
@@ -2236,6 +2235,10 @@ 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})
 
+build_info(llext-edk file PATH ${llext_edk_file})
+build_info(llext-edk cflags VALUE ${llext_edk_cflags} GENEX)
+build_info(llext-edk include-dirs VALUE "$<TARGET_PROPERTY:zephyr_interface,INTERFACE_INCLUDE_DIRECTORIES>" GENEX)
+
 add_custom_command(
     OUTPUT ${llext_edk_file}
     # Regenerate syscalls in case CONFIG_LLEXT_EDK_USERSPACE_ONLY
@@ -2252,15 +2255,6 @@ add_custom_command(
         ${SYSCALL_LONG_REGISTERS_ARG}
         ${SYSCALL_SPLIT_TIMEOUT_ARG}
     COMMAND ${CMAKE_COMMAND}
-        -DPROJECT_BINARY_DIR=${PROJECT_BINARY_DIR}
-        -DAPPLICATION_SOURCE_DIR=${APPLICATION_SOURCE_DIR}
-        -DINTERFACE_INCLUDE_DIRECTORIES="$<TARGET_PROPERTY:zephyr_interface,INTERFACE_INCLUDE_DIRECTORIES>"
-        -Dllext_edk_file=${llext_edk_file}
-        -Dllext_edk_cflags="${llext_edk_cflags}"
-        -Dllext_edk_name=${CONFIG_LLEXT_EDK_NAME}
-        -DWEST_TOPDIR=${WEST_TOPDIR}
-        -DZEPHYR_BASE=${ZEPHYR_BASE}
-        -DCONFIG_LLEXT_EDK_USERSPACE_ONLY=${CONFIG_LLEXT_EDK_USERSPACE_ONLY}
         -P ${ZEPHYR_BASE}/cmake/llext-edk.cmake
     DEPENDS ${logical_target_for_zephyr_elf}
     COMMAND_EXPAND_LISTS
@@ -2286,9 +2280,8 @@ add_subdirectory_ifdef(
 
 toolchain_linker_finalize()
 
-yaml_context(EXISTS NAME build_info result)
-if(result)
-  build_info(zephyr version VALUE ${PROJECT_VERSION_STR})
-  build_info(zephyr zephyr-base VALUE ${ZEPHYR_BASE})
-  yaml_save(NAME build_info)
-endif()
+# export build information
+build_info(zephyr version VALUE ${PROJECT_VERSION_STR})
+build_info(zephyr zephyr-base VALUE ${ZEPHYR_BASE})
+
+yaml_save(NAME build_info TARGET ${logical_target_for_zephyr_elf})

cmake/llext-edk.cmake

@@ -11,33 +11,31 @@
 # directories (build/zephyr, zephyr base, west top dir and application source
 # dir), to avoid leaking any information about the host system.
 #
-# The following arguments are expected:
-# - llext_edk_name: Name of the extension, used to name the tarball and the
-#   install directory variable for Makefile.
-# - INTERFACE_INCLUDE_DIRECTORIES: List of include directories to copy headers
-#   from. It should simply be the INTERFACE_INCLUDE_DIRECTORIES property of the
-#   zephyr_interface target.
-# - llext_edk_file: Output file name for the tarball.
-# - llext_edk_cflags: Flags to be used for source compile commands.
-# - ZEPHYR_BASE: Path to the zephyr base directory.
-# - WEST_TOPDIR: Path to the west top directory.
-# - APPLICATION_SOURCE_DIR: Path to the application source directory.
-# - PROJECT_BINARY_DIR: Path to the project binary build directory.
-# - CONFIG_LLEXT_EDK_USERSPACE_ONLY: Whether to copy syscall headers from the
-#   edk directory. This is necessary when building an extension that only
-#   supports userspace, as the syscall headers are regenerated in the edk
-#   directory.
+# The script expects a build_info.yml file in the project binary directory.
+# This file should contain the following entries:
+#  - cmake application source-dir
+#  - cmake llext-edk cflags
+#  - cmake llext-edk file
+#  - cmake llext-edk include-dirs
+#  - west topdir
 
 cmake_minimum_required(VERSION 3.20.0)
 
+# initialize the same paths as the main CMakeLists.txt for consistency
+set(PROJECT_BINARY_DIR ${CMAKE_BINARY_DIR})
+set(ZEPHYR_BASE ${CMAKE_CURRENT_LIST_DIR}/../)
+list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/modules")
+include(extensions)
+include(yaml)
+
+# read in computed build configuration
+import_kconfig(CONFIG ${PROJECT_BINARY_DIR}/.config)
+
 if (CONFIG_LLEXT_EXPORT_BUILTINS_BY_SLID)
   message(FATAL_ERROR
     "The LLEXT EDK is not compatible with CONFIG_LLEXT_EXPORT_BUILTINS_BY_SLID.")
 endif()
 
-set(llext_edk ${PROJECT_BINARY_DIR}/${llext_edk_name})
-set(llext_edk_inc ${llext_edk}/include)
-
 # Usage:
 #   relative_dir(<dir> <relative_out> <bindir_out>)
 #
@@ -89,12 +87,23 @@ function(relative_dir dir relative_out bindir_out)
     endif()
 endfunction()
 
+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_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)
+yaml_get(WEST_TOPDIR NAME build_info KEY west topdir)
+
+set(llext_edk_name ${CONFIG_LLEXT_EDK_NAME})
+set(llext_edk ${PROJECT_BINARY_DIR}/${llext_edk_name})
+set(llext_edk_inc ${llext_edk}/include)
+
 string(REGEX REPLACE "[^a-zA-Z0-9]" "_" llext_edk_name_sane ${llext_edk_name})
 string(TOUPPER ${llext_edk_name_sane} llext_edk_name_sane)
 set(install_dir_var "${llext_edk_name_sane}_INSTALL_DIR")
 
-separate_arguments(llext_edk_cflags NATIVE_COMMAND ${llext_edk_cflags})
-
 set(make_relative FALSE)
 foreach(flag ${llext_edk_cflags})
     if (flag STREQUAL "-imacros")
@@ -106,24 +115,20 @@ foreach(flag ${llext_edk_cflags})
         relative_dir(${parent} dest bindir)
         cmake_path(RELATIVE_PATH dest BASE_DIRECTORY ${llext_edk} OUTPUT_VARIABLE dest_rel)
         if(bindir)
-            list(APPEND imacros_gen_make "-imacros\$(${install_dir_var})/${dest_rel}/${name}")
-            list(APPEND imacros_gen_cmake "-imacros\${CMAKE_CURRENT_LIST_DIR}/${dest_rel}/${name}")
+            list(APPEND imacros_gen "@DASHIMACROS@${dest_rel}/${name}")
         else()
-            list(APPEND imacros_make "-imacros\$(${install_dir_var})/${dest_rel}/${name}")
-            list(APPEND imacros_cmake "-imacros\${CMAKE_CURRENT_LIST_DIR}/${dest_rel}/${name}")
+            list(APPEND imacros "@DASHIMACROS@${dest_rel}/${name}")
         endif()
     else()
         list(APPEND new_cflags ${flag})
     endif()
 endforeach()
 set(llext_edk_cflags ${new_cflags})
 
-list(APPEND base_flags_make ${llext_edk_cflags} ${imacros_make})
-list(APPEND base_flags_cmake ${llext_edk_cflags} ${imacros_cmake})
+list(APPEND base_flags ${llext_edk_cflags} ${imacros})
 
-separate_arguments(include_dirs NATIVE_COMMAND ${INTERFACE_INCLUDE_DIRECTORIES})
 file(MAKE_DIRECTORY ${llext_edk_inc})
-foreach(dir ${include_dirs})
+foreach(dir ${INTERFACE_INCLUDE_DIRECTORIES})
     if (NOT EXISTS ${dir})
         continue()
     endif()
@@ -137,54 +142,85 @@ foreach(dir ${include_dirs})
 
     cmake_path(RELATIVE_PATH dest BASE_DIRECTORY ${llext_edk} OUTPUT_VARIABLE dest_rel)
     if(bindir)
-        list(APPEND inc_gen_flags_make "-I\$(${install_dir_var})/${dest_rel}")
-        list(APPEND inc_gen_flags_cmake "-I\${CMAKE_CURRENT_LIST_DIR}/${dest_rel}")
+        list(APPEND gen_inc_flags "@DASHI@${dest_rel}")
     else()
-        list(APPEND inc_flags_make "-I\$(${install_dir_var})/${dest_rel}")
-        list(APPEND inc_flags_cmake "-I\${CMAKE_CURRENT_LIST_DIR}/${dest_rel}")
+        list(APPEND inc_flags "@DASHI@${dest_rel}")
     endif()
-    list(APPEND all_inc_flags_make "-I\$(${install_dir_var})/${dest_rel}")
-    list(APPEND all_inc_flags_cmake "-I\${CMAKE_CURRENT_LIST_DIR}/${dest_rel}")
+    list(APPEND all_inc_flags "@DASHI@${dest_rel}")
 endforeach()
 
+list(APPEND all_flags ${base_flags} ${imacros_gen} ${all_inc_flags})
+
 if(CONFIG_LLEXT_EDK_USERSPACE_ONLY)
     # Copy syscall headers from edk directory, as they were regenerated there.
     file(COPY ${PROJECT_BINARY_DIR}/edk/include/generated/ DESTINATION ${llext_edk_inc}/zephyr/include/generated)
 endif()
 
-# Generate flags for Makefile
-list(APPEND all_flags_make ${base_flags_make} ${imacros_gen_make} ${all_inc_flags_make})
-list(JOIN all_flags_make " " all_flags_str)
-file(WRITE ${llext_edk}/Makefile.cflags "LLEXT_CFLAGS = ${all_flags_str}")
 
-list(JOIN all_inc_flags_make " " all_inc_flags_str)
-file(APPEND ${llext_edk}/Makefile.cflags "\n\nLLEXT_ALL_INCLUDE_CFLAGS = ${all_inc_flags_str}")
-
-list(JOIN inc_flags_make " " inc_flags_str)
-file(APPEND ${llext_edk}/Makefile.cflags "\n\nLLEXT_INCLUDE_CFLAGS = ${inc_flags_str}")
-
-list(JOIN inc_gen_flags_make " " inc_gen_flags_str)
-file(APPEND ${llext_edk}/Makefile.cflags "\n\nLLEXT_GENERATED_INCLUDE_CFLAGS = ${inc_gen_flags_str}")
-
-list(JOIN base_flags_make " " base_flags_str)
-file(APPEND ${llext_edk}/Makefile.cflags "\n\nLLEXT_BASE_CFLAGS = ${base_flags_str}")
+#
+# Generate the EDK flags files
+#
 
-list(JOIN imacros_gen_make " " imacros_gen_str)
-file(APPEND ${llext_edk}/Makefile.cflags "\n\nLLEXT_GENERATED_IMACROS_CFLAGS = ${imacros_gen_str}")
+set(edk_targets MAKEFILE CMAKE)
+set(edk_file_MAKEFILE ${llext_edk}/Makefile.cflags)
+set(edk_file_CMAKE ${llext_edk}/cmake.cflags)
 
-# Generate flags for CMake
-list(APPEND all_flags_cmake ${base_flags_cmake} ${imacros_gen_cmake} ${all_inc_flags_cmake})
-file(WRITE ${llext_edk}/cmake.cflags "set(LLEXT_CFLAGS ${all_flags_cmake})")
+# Escape problematic characters in a string
+function(edk_escape target str_in str_out)
+    string(REPLACE "\\" "\\\\" str_escaped "${str_in}")
+    string(REPLACE "\"" "\\\"" str_escaped "${str_escaped}")
+    set(${str_out} "${str_escaped}" PARENT_SCOPE)
+endfunction()
 
-file(APPEND ${llext_edk}/cmake.cflags "\n\nset(LLEXT_ALL_INCLUDE_CFLAGS ${all_inc_flags_cmake})")
+# Clear the contents of the requested file
+function(edk_write_header target)
+    file(WRITE ${edk_file_${target}} "")
+endfunction()
 
-file(APPEND ${llext_edk}/cmake.cflags "\n\nset(LLEXT_INCLUDE_CFLAGS ${inc_flags_cmake})")
+# Mark a section in the file with a single line comment
+function(edk_write_comment target comment)
+    file(APPEND ${edk_file_${target}} "\n# ${comment}\n")
+endfunction()
 
-file(APPEND ${llext_edk}/cmake.cflags "\n\nset(LLEXT_GENERATED_INCLUDE_CFLAGS ${inc_gen_flags_cmake})")
+# Define a variable in the file
+function(edk_write_var target var_name var_value)
+    if(target STREQUAL "CMAKE")
+        # CMake: export assignments of the form:
+        #
+        #   set(var "value1;value2;...")
+        #
+        set(DASHIMACROS "-imacros\${CMAKE_CURRENT_LIST_DIR}/")
+        set(DASHI "-I\${CMAKE_CURRENT_LIST_DIR}/")
+        edk_escape(${target} "${var_value}" var_value)
+        string(CONFIGURE "${var_value}" exp_var_value @ONLY)
+        # The list is otherwise exported verbatim, surrounded by quotes.
+        file(APPEND ${edk_file_${target}} "set(${var_name} \"${exp_var_value}\")\n")
+    elseif(target STREQUAL "MAKEFILE")
+        # Makefile: export assignments of the form:
+        #
+        #   var = "value1" "value2" ...
+        #
+        set(DASHIMACROS "-imacros\$(${install_dir_var})/")
+        set(DASHI "-I\$(${install_dir_var})/")
+        edk_escape(${target} "${var_value}" var_value)
+        string(CONFIGURE "${var_value}" exp_var_value @ONLY)
+        # Each element of the list is wrapped in quotes and is separated by a space.
+        list(JOIN exp_var_value "\" \"" exp_var_value_str)
+        file(APPEND ${edk_file_${target}} "${var_name} = \"${exp_var_value_str}\"\n")
+    endif()
+endfunction()
 
-file(APPEND ${llext_edk}/cmake.cflags "\n\nset(LLEXT_BASE_CFLAGS ${base_flags_cmake})")
+foreach(target ${edk_targets})
+    edk_write_header(${target})
 
-file(APPEND ${llext_edk}/cmake.cflags "\n\nset(LLEXT_GENERATED_IMACROS_CFLAGS ${imacros_gen_cmake})")
+    edk_write_comment(${target} "Compile flags")
+    edk_write_var(${target} "LLEXT_CFLAGS" "${all_flags}")
+    edk_write_var(${target} "LLEXT_ALL_INCLUDE_CFLAGS" "${all_inc_flags}")
+    edk_write_var(${target} "LLEXT_INCLUDE_CFLAGS" "${inc_flags}")
+    edk_write_var(${target} "LLEXT_GENERATED_INCLUDE_CFLAGS" "${gen_inc_flags}")
+    edk_write_var(${target} "LLEXT_BASE_CFLAGS" "${base_flags}")
+    edk_write_var(${target} "LLEXT_GENERATED_IMACROS_CFLAGS" "${imacros_gen}")
+endforeach()
 
 # Generate the tarball
 file(ARCHIVE_CREATE

cmake/modules/extensions.cmake

@@ -3703,10 +3703,10 @@ function(topological_sort)
 endfunction()
 
 # Usage:
-#   build_info(<tag>... VALUE <value>... )
+#   build_info(<tag>... VALUE <value>... [GENEX])
 #   build_info(<tag>... PATH  <path>... )
 #
-# This function populates updates the build_info.yml info file with exchangable build information
+# This function populates the build_info.yml info file with exchangable build information
 # related to the current build.
 #
 # Example:
@@ -3724,17 +3724,27 @@ endfunction()
 # PATH  <path>... : path(s) to place in the build_info.yml file. All paths are converted to CMake
 #                   style. If no conversion is required, for example when paths are already
 #                   guaranteed to be CMake style, then VALUE can also be used.
+# GENEX : the value(s) contain a generator expression. Cannot be used with PATH.
+#         Resulting context must be saved providing a TARGET to yaml_save().
 function(build_info)
-  set(convert_path FALSE)
-  set(arg_list ${ARGV})
-  list(FIND arg_list VALUE index)
-  if(index EQUAL -1)
-    list(FIND arg_list PATH index)
+  cmake_parse_arguments(ARG_BUILD_INFO "GENEX" "" "VALUE;PATH" ${ARGN})
+
+  zephyr_check_arguments_required_allow_empty(${CMAKE_CURRENT_FUNCTION} ARG_BUILD_INFO VALUE PATH)
+  zephyr_check_arguments_exclusive(${CMAKE_CURRENT_FUNCTION} ARG_BUILD_INFO VALUE PATH)
+
+  set(keys ${ARG_BUILD_INFO_UNPARSED_ARGUMENTS})
+  if (DEFINED ARG_BUILD_INFO_PATH)
     set(convert_path TRUE)
+    set(values ${ARG_BUILD_INFO_PATH})
+  else()
+    set(convert_path FALSE)
+    set(values ${ARG_BUILD_INFO_VALUE})
   endif()
-
-  if(index EQUAL -1)
-    message(FATAL_ERROR "${CMAKE_CURRENT_FUNCTION}(...) missing a required argument: VALUE or PATH")
+  if (ARG_BUILD_INFO_GENEX)
+    if (convert_path)
+      message(FATAL_ERROR "build_info: GENEX is unsupported on PATH entries")
+    endif()
+    set(genex_flag "GENEX")
   endif()
 
   yaml_context(EXISTS NAME build_info result)
@@ -3748,10 +3758,6 @@ function(build_info)
     yaml_set(NAME build_info KEY version VALUE "0.1.0")
   endif()
 
-  list(SUBLIST arg_list 0 ${index} keys)
-  list(SUBLIST arg_list ${index} -1 values)
-  list(POP_FRONT values)
-
   if(convert_path)
     set(converted_values)
     foreach(val ${values})
@@ -3779,7 +3785,7 @@ function(build_info)
     endif()
   endif()
 
-  yaml_set(NAME build_info KEY cmake ${keys} ${type} "${values}")
+  yaml_set(NAME build_info KEY cmake ${keys} ${type} "${values}" ${genex_flag})
 endfunction()
 
 ########################################################
@@ -5916,7 +5922,7 @@ endfunction()
 # depending on the exact use of the function in script mode.
 #
 # Current Zephyr CMake scripts which includes `extensions.cmake` in script mode
-# are: package_helper.cmake, verify-toolchain.cmake
+# are: package_helper.cmake, verify-toolchain.cmake, llext-edk.cmake
 #
 
 if(CMAKE_SCRIPT_MODE_FILE)