cmake: generate the complete .config at configuration time.

CMakeLists.txt

@@ -17,6 +17,17 @@ if(NOT (${CMAKE_VERSION} VERSION_LESS "3.13.0"))
 	cmake_policy(SET CMP0079 OLD)
 endif()
 
+if(${CMAKE_VERSION} VERSION_LESS "3.12.0")
+	# FindPythonInterp is bugged and may sometimes be unable to find
+	# Python 3 when both Python 2 & 3 are in PATH,
+	# so it's always better to use CMake 3.12+
+	find_package(PythonInterp 3.0)
+	set(PYTHON3 "${PYTHON_EXECUTABLE}")
+else()
+	find_package(Python3 COMPONENTS Interpreter)
+	set(PYTHON3 "${Python3_EXECUTABLE}")
+endif()
+
 option(BUILD_UNIT_TESTS "Build unit tests" OFF)
 option(BUILD_CLANG_SCAN "Build for clang's scan-build" OFF)
 
@@ -95,30 +106,14 @@ include(scripts/cmake/version.cmake)
 
 include(scripts/cmake/dist.cmake)
 
-# cmake itself cannot depend on files that don't exist
-# so to make it regenerate when .config file is created,
-# we make it depend on containing directory
-# NOTE: some filesystems may be unable to watch directory change,
-# in that case cmake may need to be regenerated from CLI
-set_property(DIRECTORY APPEND PROPERTY CMAKE_CONFIGURE_DEPENDS
-	${GENERATED_DIRECTORY} ${DOT_CONFIG_PATH})
-
-if(EXISTS ${DOT_CONFIG_PATH})
-	read_kconfig_config(${DOT_CONFIG_PATH})
-endif()
-
-if(${CMAKE_VERSION} VERSION_LESS "3.12.0")
-	# FindPythonInterp is bugged and may sometimes be unable to find
-	# Python 3 when both Python 2 & 3 are in PATH,
-	# so it's always better to use CMake 3.12+
-	find_package(PythonInterp 3.0)
-	set(PYTHON3 "${PYTHON_EXECUTABLE}")
-else()
-	find_package(Python3 COMPONENTS Interpreter)
-	set(PYTHON3 "${Python3_EXECUTABLE}")
-endif()
-
 include(scripts/cmake/kconfig.cmake)
+read_kconfig_config(${DOT_CONFIG_PATH})
+
+# FIXME: this successful triggers CMake to re-run, however -imacros
+# hides the generated .h dependency from CMake and most sources are NOT
+# recompiled.
+set_property(DIRECTORY APPEND
+	PROPERTY CMAKE_CONFIGURE_DEPENDS ${DOT_CONFIG_PATH})
 
 add_dependencies(sof_public_headers genconfig check_version_h)
 target_include_directories(sof_public_headers INTERFACE ${GENERATED_DIRECTORY}/include)

scripts/cmake/defconfigs.cmake

@@ -1,6 +1,6 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
-# Looks for defconfig files in arch directory
+# Looks for defconfig files in arch directories where kconfig.cmake looks too.
 set(DEFCONFIGS_DIRECTORY "${PROJECT_SOURCE_DIR}/src/arch/${ARCH}/configs")
 file(GLOB DEFCONFIG_PATHS "${DEFCONFIGS_DIRECTORY}/*_defconfig")
 

scripts/cmake/kconfig.cmake

@@ -1,9 +1,105 @@
 # SPDX-License-Identifier: BSD-3-Clause
 
-# Kconfig targets
-
 include(${CMAKE_CURRENT_LIST_DIR}/defconfigs.cmake)
 
+
+ ### configure-time .config ###
+
+
+if(NOT INIT_CONFIG_found)
+# Brand new build directory, search for initial configuration
+
+# Default value when no -DINIT_CONFIG on the command line
+set(INIT_CONFIG "initial.config" CACHE STRING "Initial .config file")
+
+# - ".' is the top source directory.
+# - "src/arch/${arch}/configs" is for convenience and compatibility with
+# defconfigs.cmake.
+# - First found wins.
+# - If two archs ever use the same platform_defconfig name then a full
+# path must be used, e.g.: -DINIT_CONFIG=src/arch/myarch/collision_defconfig
+
+set(init_config_search_list ".")
+foreach(arch "xtensa" "host")
+list(APPEND init_config_search_list "src/arch/${arch}/configs")
+endforeach()
+
+find_file(INIT_CONFIG_found
+	NAMES ${INIT_CONFIG}
+	NO_CMAKE_FIND_ROOT_PATH
+	NO_DEFAULT_PATH
+	PATHS ${init_config_search_list}
+)
+
+else() # old build directory
+
+if (INIT_CONFIG)
+message(WARNING
+	"IGNORING '-DINIT_CONFIG=${INIT_CONFIG}!!' "
+	"Using up-to-date ${INIT_CONFIG_found} instead."
+)
+endif()
+
+endif() # new/old build directory
+
+
+if(NOT INIT_CONFIG_found)
+message(FATAL_ERROR
+	"Initial configuration missing, no ${INIT_CONFIG} found. "
+	"Provide a ${PROJECT_SOURCE_DIR}/initial.config file or specify some "
+	"other -DINIT_CONFIG=location relative to '${PROJECT_SOURCE_DIR}/' or "
+	"'${PROJECT_SOURCE_DIR}/src/arch/*/configs/'"
+)
+endif()
+
+# Did someone or something remove our generated/.config?
+if(NOT EXISTS ${INIT_CONFIG_found})
+message(FATAL_ERROR "The file ${INIT_CONFIG_found} vanished!")
+endif()
+
+# Don't confuse this configure-time, .config generation with
+# the build-time, autoconfig.h genconfig target below
+message(STATUS
+	"(Re-)generating ${DOT_CONFIG_PATH}\n"
+	" and ${CONFIG_H_PATH}\n"
+	" from ${INIT_CONFIG_found}"
+)
+execute_process(
+	COMMAND ${CMAKE_COMMAND} -E env
+ KCONFIG_CONFIG=${INIT_CONFIG_found}
+ srctree=${PROJECT_SOURCE_DIR}
+ CC_VERSION_TEXT=${CC_VERSION_TEXT}
+ ARCH=${ARCH}
+ ${PYTHON3} ${PROJECT_SOURCE_DIR}/scripts/kconfig/genconfig.py
+ --config-out=${DOT_CONFIG_PATH}
+ --header-path ${CONFIG_H_PATH}
+ ${PROJECT_SOURCE_DIR}/Kconfig
+	WORKING_DIRECTORY ${GENERATED_DIRECTORY}
+	# Available only from CMake 3.18. Amazingly not the default.
+	# COMMAND_ERROR_IS_FATAL ANY
+	RESULT_VARIABLE _genret
+)
+if(${_genret})
+message(FATAL_ERROR
+ "genconfig.py from ${INIT_CONFIG_found} to ${DOT_CONFIG_PATH} failed")
+endif()
+
+if(NOT ${INIT_CONFIG_found} STREQUAL ${DOT_CONFIG_PATH})
+# Brand new build directory and config.
+message(STATUS
+	"Done, future changes to ${INIT_CONFIG_found}\n"
+	" will be IGNORED by this build directory! The primary .config\n"
+	" file is now 'generated/.config' in the build directory."
+)
+endif()
+# Now force CMake to forget about the initial config and to re-use our
+# own private ${DOT_CONFIG_PATH} when it decides it must re-run itself.
+unset(INIT_CONFIG CACHE)
+set(INIT_CONFIG_found ${DOT_CONFIG_PATH} CACHE FILEPATH "active .config" FORCE)
+
+
+ ### build-time Kconfig targets ###
+
 add_custom_target(
 	menuconfig
 	COMMAND ${CMAKE_COMMAND} -E env
@@ -33,24 +129,9 @@ add_custom_target(
 
 file(GLOB_RECURSE KCONFIG_FILES "${SOF_ROOT_SOURCE_DIRECTORY}/Kconfig")
 
-if(EXISTS ${DOT_CONFIG_PATH})
-	# Update with olddefconfig only if config was previously generated
-	add_custom_command(
- OUTPUT ${DOT_CONFIG_PATH}
- COMMAND ${CMAKE_COMMAND} -E env
- srctree=${PROJECT_SOURCE_DIR}
- CC_VERSION_TEXT=${CC_VERSION_TEXT}
- ARCH=${ARCH}
- ${PYTHON3} ${PROJECT_SOURCE_DIR}/scripts/kconfig/olddefconfig.py
- ${PROJECT_SOURCE_DIR}/Kconfig
- DEPENDS ${KCONFIG_FILES}
- WORKING_DIRECTORY ${GENERATED_DIRECTORY}
- COMMENT "Regenerating .config with olddefconfig"
- VERBATIM
- USES_TERMINAL
-	)
-endif()
 
+# Don't confuse this build-time, .h target with the
+# configure-time, .config genconfig above.
 add_custom_command(
 	OUTPUT ${CONFIG_H_PATH}
 	COMMAND ${CMAKE_COMMAND} -E env

scripts/cmake/misc.cmake

@@ -35,6 +35,8 @@ function(get_optimization_flag OUT_VAR)
  set(${OUT_VAR} "Og" PARENT_SCOPE)
 	elseif(CONFIG_OPTIMIZE_FOR_NONE)
  set(${OUT_VAR} "O0" PARENT_SCOPE)
+	else()
+ message(FATAL_ERROR "no CONFIG_OPTIMIZE_ found")
 	endif()
 endfunction()
 
@@ -54,6 +56,12 @@ function(add_local_sources target)
  endif()
 
  target_sources(${target} PRIVATE ${path})
+	# -imacros${CONFIG_H_PATH} escapes regular .h dep scanning
+	#	add_dependencies(${target} genconfig) # has no effect?
+ set_source_files_properties(${path}
+ PROPERTIES
+ OBJECT_DEPENDS ${CONFIG_H_PATH}
+ )
 	endforeach()
 endfunction()
 

scripts/xtensa-build-all.sh

@@ -352,9 +352,8 @@ do
  -DMEU_OPENSSL="${MEU_OPENSSL}" \
  "${MEU_PATH_OPTION}" \
  "${PRIVATE_KEY_OPTION}" \
+ -DINIT_CONFIG=${PLATFORM}${DEFCONFIG_PATCH}_defconfig \
  "$SOF_TOP"
-
-	cmake --build . -- ${PLATFORM}${DEFCONFIG_PATCH}_defconfig
 	)
 
 	if [ -n "$OVERRIDE_CONFIG" ]

src/arch/xtensa/CMakeLists.txt

@@ -130,9 +130,6 @@ endif()
 # linker scripts
 
 function(sof_add_ld_script binary_name script_name)
-	if(NOT EXISTS ${DOT_CONFIG_PATH})
- return()
-	endif()
 
 	set(lds_in ${PROJECT_SOURCE_DIR}/src/platform/${platform_folder}/${script_name}.in)
 	set(lds_out ${PROJECT_BINARY_DIR}/${script_name})

tools/oss-fuzz/CMakeLists.txt

@@ -42,18 +42,11 @@ ExternalProject_Add(sof_ep
  -DCMAKE_INSTALL_PREFIX=${sof_install_directory}
  -DCMAKE_VERBOSE_MAKEFILE=${CMAKE_VERBOSE_MAKEFILE}
  -DCONFIG_H_PATH=${config_h}
+ -DINIT_CONFIG=library_defconfig
 	BUILD_ALWAYS 1
 	BUILD_BYPRODUCTS "${sof_install_directory}/lib/libsof.so"
 )
 
-ExternalProject_Add_Step(
-	sof_ep defconfig
-	COMMAND ${CMAKE_COMMAND} --build . --target library_defconfig
-	DEPENDEES configure
-	DEPENDERS build
-	WORKING_DIRECTORY "${sof_binary_directory}"
-)
-
 add_library(sof_library STATIC IMPORTED)
 set_target_properties(sof_library PROPERTIES IMPORTED_LOCATION "${sof_install_directory}/lib/libsof.a")
 add_dependencies(sof_library sof_ep)

tools/testbench/CMakeLists.txt

@@ -41,19 +41,12 @@ ExternalProject_Add(sof_ep
 	CMAKE_ARGS -DCONFIG_LIBRARY=ON
  -DCMAKE_INSTALL_PREFIX=${sof_install_directory}
  -DCMAKE_VERBOSE_MAKEFILE=${CMAKE_VERBOSE_MAKEFILE}
+ -DINIT_CONFIG=library_defconfig
  -DCONFIG_H_PATH=${config_h}
 	BUILD_ALWAYS 1
 	BUILD_BYPRODUCTS "${sof_install_directory}/lib/libsof.so"
 )
 
-ExternalProject_Add_Step(
-	sof_ep defconfig
-	COMMAND ${CMAKE_COMMAND} --build . --target library_defconfig
-	DEPENDEES configure
-	DEPENDERS build
-	WORKING_DIRECTORY "${sof_binary_directory}"
-)
-
 add_library(sof_library SHARED IMPORTED)
 set_target_properties(sof_library PROPERTIES IMPORTED_LOCATION "${sof_install_directory}/lib/libsof.so")
 add_dependencies(sof_library sof_ep)