zephyr/cmake/modules/snippets.cmake

122 lines
4.0 KiB
CMake

# SPDX-License-Identifier: Apache-2.0
#
# Copyright (c) 2021, Nordic Semiconductor ASA
# Snippets support
#
# This module:
#
# - searches for snippets in zephyr and any modules
# - validates the SNIPPET input variable, if any
#
# If SNIPPET contains a snippet name that is not found, an error
# will be raised, and the list of valid snippets will be printed.
#
# Outcome:
# The following variables will be defined when this module completes:
#
# - SNIPPET_AS_LIST: CMake list of snippet names, created from the
# SNIPPET variable
# - SNIPPET_ROOT: CMake list of snippet roots, deduplicated and with
# ZEPHYR_BASE appended at the end
#
# The following variables may be updated when this module completes:
# - DTC_OVERLAY_FILE
# - OVERLAY_CONFIG
#
# The following targets will be defined when this CMake module completes:
# - snippets: when invoked, a list of valid snippets will be printed
#
# Optional variables:
# - SNIPPET_ROOT: input CMake list of snippet roots (directories containing
# additional snippet implementations); this should not include ZEPHYR_BASE,
# as that will be added by this module
include_guard(GLOBAL)
include(extensions)
# Warn the user if SNIPPET changes later. Such changes are ignored.
zephyr_check_cache(SNIPPET WATCH)
# Putting the body into a function prevents us from polluting the
# parent scope. We'll set our outcome variables in the parent scope of
# the function to ensure the outcome of the module.
function(zephyr_process_snippets)
set(snippets_py ${ZEPHYR_BASE}/scripts/snippets.py)
set(snippets_generated ${CMAKE_BINARY_DIR}/zephyr/snippets_generated.cmake)
# Set SNIPPET_AS_LIST, removing snippets_generated.cmake if we are
# running cmake again and snippets are no longer requested.
if (NOT DEFINED SNIPPET)
set(SNIPPET_AS_LIST "" PARENT_SCOPE)
file(REMOVE ${snippets_generated})
else()
string(REPLACE " " ";" SNIPPET_AS_LIST "${SNIPPET}")
set(SNIPPET_AS_LIST "${SNIPPET_AS_LIST}" PARENT_SCOPE)
endif()
# Set SNIPPET_ROOT.
list(APPEND SNIPPET_ROOT ${APPLICATION_SOURCE_DIR})
list(APPEND SNIPPET_ROOT ${ZEPHYR_BASE})
unset(real_snippet_root)
foreach(snippet_dir ${SNIPPET_ROOT})
# The user might have put a symbolic link in here, for example.
file(REAL_PATH ${snippet_dir} real_snippet_dir)
list(APPEND real_snippet_root ${real_snippet_dir})
endforeach()
set(SNIPPET_ROOT ${real_snippet_root})
list(REMOVE_DUPLICATES SNIPPET_ROOT)
set(SNIPPET_ROOT "${SNIPPET_ROOT}" PARENT_SCOPE)
# Generate and include snippets_generated.cmake.
# The Python script is responsible for checking for unknown
# snippets.
set(snippet_root_args)
foreach(root IN LISTS SNIPPET_ROOT)
list(APPEND snippet_root_args --snippet-root "${root}")
endforeach()
set(requested_snippet_args)
foreach(snippet_name ${SNIPPET_AS_LIST})
list(APPEND requested_snippet_args --snippet "${snippet_name}")
endforeach()
execute_process(COMMAND ${PYTHON_EXECUTABLE}
${snippets_py}
${snippet_root_args}
${requested_snippet_args}
--cmake-out ${snippets_generated}
OUTPUT_VARIABLE output
ERROR_VARIABLE output
RESULT_VARIABLE ret)
if(${ret})
message(FATAL_ERROR "${output}")
endif()
include(${snippets_generated})
# Create the 'snippets' target. Each snippet is printed in a
# separate command because build system files are not fond of
# newlines.
list(TRANSFORM SNIPPET_NAMES PREPEND "COMMAND;${CMAKE_COMMAND};-E;echo;"
OUTPUT_VARIABLE snippets_target_cmd)
add_custom_target(snippets ${snippets_target_cmd} USES_TERMINAL)
# If snippets were requested, print messages for each one.
if(SNIPPET_AS_LIST)
# Print the requested snippets.
set(snippet_names "Snippet(s):")
foreach(snippet IN LISTS SNIPPET_AS_LIST)
string(APPEND snippet_names " ${snippet}")
endforeach()
message(STATUS "${snippet_names}")
endif()
# Re-run cmake if any files we depend on changed.
set_property(DIRECTORY APPEND PROPERTY
CMAKE_CONFIGURE_DEPENDS
${snippets_py}
${SNIPPET_PATHS} # generated variable
)
endfunction()
zephyr_process_snippets()