blob: 82fff013efbc3bc0387b4a8677a1040ce9113bf8 [file] [log] [blame]
include(CheckCCompilerFlag)
include(CheckCXXCompilerFlag)
########################################################
# Table of contents
########################################################
# 1. Zephyr-aware extensions
# 1.1. zephyr_*
# 1.2. zephyr_library_*
# 1.3. generate_inc_*
# 2. Kconfig-aware extensions
# 2.1 *_if_kconfig
# 2.2 Misc
# 3. CMake-generic extensions
# 3.1. *_ifdef
# 3.2. *_ifndef
# 3.3. *_option compiler compatibility checks
# 3.4. Debugging CMake
########################################################
# 1. Zephyr-aware extensions
########################################################
# 1.1. zephyr_*
#
# The following methods are for modifying the CMake library[0] called
# "zephyr". zephyr is a catchall CMake library for source files that
# can be built purely with the include paths, defines, and other
# compiler flags that all zephyr source files use.
# [0] https://cmake.org/cmake/help/latest/manual/cmake-buildsystem.7.html
#
# Example usage:
# zephyr_sources(
# random_esp32.c
# utils.c
# )
#
# Is short for:
# target_sources(zephyr PRIVATE
# ${CMAKE_CURRENT_SOURCE_DIR}/random_esp32.c
# ${CMAKE_CURRENT_SOURCE_DIR}/utils.c
# )
# https://cmake.org/cmake/help/latest/command/target_sources.html
function(zephyr_sources)
foreach(arg ${ARGV})
if(IS_ABSOLUTE ${arg})
set(path ${arg})
else()
set(path ${CMAKE_CURRENT_SOURCE_DIR}/${arg})
endif()
if(IS_DIRECTORY ${path})
message(FATAL_ERROR "zephyr_sources() was called on a directory")
endif()
target_sources(zephyr PRIVATE ${path})
endforeach()
endfunction()
# https://cmake.org/cmake/help/latest/command/target_include_directories.html
function(zephyr_include_directories)
foreach(arg ${ARGV})
if(IS_ABSOLUTE ${arg})
set(path ${arg})
else()
set(path ${CMAKE_CURRENT_SOURCE_DIR}/${arg})
endif()
target_include_directories(zephyr_interface INTERFACE ${path})
endforeach()
endfunction()
# https://cmake.org/cmake/help/latest/command/target_include_directories.html
function(zephyr_system_include_directories)
foreach(arg ${ARGV})
if(IS_ABSOLUTE ${arg})
set(path ${arg})
else()
set(path ${CMAKE_CURRENT_SOURCE_DIR}/${arg})
endif()
target_include_directories(zephyr_interface SYSTEM INTERFACE ${path})
endforeach()
endfunction()
# https://cmake.org/cmake/help/latest/command/target_compile_definitions.html
function(zephyr_compile_definitions)
target_compile_definitions(zephyr_interface INTERFACE ${ARGV})
endfunction()
# https://cmake.org/cmake/help/latest/command/target_compile_options.html
function(zephyr_compile_options)
target_compile_options(zephyr_interface INTERFACE ${ARGV})
endfunction()
# https://cmake.org/cmake/help/latest/command/target_link_libraries.html
function(zephyr_link_libraries)
target_link_libraries(zephyr_interface INTERFACE ${ARGV})
endfunction()
# See this file section 3.1. target_cc_option
function(zephyr_cc_option)
foreach(arg ${ARGV})
target_cc_option(zephyr_interface INTERFACE ${arg})
endforeach()
endfunction()
function(zephyr_cc_option_fallback option1 option2)
target_cc_option_fallback(zephyr_interface INTERFACE ${option1} ${option2})
endfunction()
function(zephyr_ld_options)
target_ld_options(zephyr_interface INTERFACE ${ARGV})
endfunction()
# Getter functions for extracting build information from
# zephyr_interface. Returning lists, and strings is supported, as is
# requesting specific categories of build information (defines,
# includes, options).
#
# The naming convention follows:
# zephyr_get_${build_information}_for_lang${format}(lang x)
# Where
# the argument 'x' is written with the result
# and
# ${build_information} can be one of
# - include_directories # -I directories
# - system_include_directories # -isystem directories
# - compile_definitions # -D'efines
# - compile_options # misc. compiler flags
# and
# ${format} can be
# - the empty string '', signifying that it should be returned as a list
# - _as_string signifying that it should be returned as a string
# and
# ${lang} can be one of
# - C
# - CXX
# - ASM
#
# e.g.
# zephyr_get_include_directories_for_lang(ASM x)
# writes "-Isome_dir;-Isome/other/dir" to x
function(zephyr_get_include_directories_for_lang_as_string lang i)
zephyr_get_include_directories_for_lang(${lang} list_of_flags)
convert_list_of_flags_to_string_of_flags(list_of_flags str_of_flags)
set(${i} ${str_of_flags} PARENT_SCOPE)
endfunction()
function(zephyr_get_system_include_directories_for_lang_as_string lang i)
zephyr_get_system_include_directories_for_lang(${lang} list_of_flags)
convert_list_of_flags_to_string_of_flags(list_of_flags str_of_flags)
set(${i} ${str_of_flags} PARENT_SCOPE)
endfunction()
function(zephyr_get_compile_definitions_for_lang_as_string lang i)
zephyr_get_compile_definitions_for_lang(${lang} list_of_flags)
convert_list_of_flags_to_string_of_flags(list_of_flags str_of_flags)
set(${i} ${str_of_flags} PARENT_SCOPE)
endfunction()
function(zephyr_get_compile_options_for_lang_as_string lang i)
zephyr_get_compile_options_for_lang(${lang} list_of_flags)
convert_list_of_flags_to_string_of_flags(list_of_flags str_of_flags)
set(${i} ${str_of_flags} PARENT_SCOPE)
endfunction()
function(zephyr_get_include_directories_for_lang lang i)
get_property_and_add_prefix(flags zephyr_interface INTERFACE_INCLUDE_DIRECTORIES -I)
process_flags(${lang} flags output_list)
set(${i} ${output_list} PARENT_SCOPE)
endfunction()
function(zephyr_get_system_include_directories_for_lang lang i)
get_property_and_add_prefix(flags zephyr_interface INTERFACE_SYSTEM_INCLUDE_DIRECTORIES -isystem)
process_flags(${lang} flags output_list)
set(${i} ${output_list} PARENT_SCOPE)
endfunction()
function(zephyr_get_compile_definitions_for_lang lang i)
get_property_and_add_prefix(flags zephyr_interface INTERFACE_COMPILE_DEFINITIONS -D)
process_flags(${lang} flags output_list)
set(${i} ${output_list} PARENT_SCOPE)
endfunction()
function(zephyr_get_compile_options_for_lang lang i)
get_property(flags TARGET zephyr_interface PROPERTY INTERFACE_COMPILE_OPTIONS)
process_flags(${lang} flags output_list)
set(${i} ${output_list} PARENT_SCOPE)
endfunction()
function(process_flags lang input output)
# The flags might contains compile language generator expressions that
# look like this:
# $<$<COMPILE_LANGUAGE:CXX>:-fno-exceptions>
#
# Flags that don't specify a language like this apply to all
# languages.
#
# See COMPILE_LANGUAGE in
# https://cmake.org/cmake/help/v3.3/manual/cmake-generator-expressions.7.html
#
# To deal with this, we apply a regex to extract the flag and also
# to find out if the language matches.
#
# If this doesn't work out we might need to ban the use of
# COMPILE_LANGUAGE and instead partition C, CXX, and ASM into
# different libraries
set(languages C CXX ASM)
set(tmp_list "")
foreach(flag ${${input}})
set(is_compile_lang_generator_expression 0)
foreach(l ${languages})
if(flag MATCHES "<COMPILE_LANGUAGE:${l}>:([^>]+)>")
set(is_compile_lang_generator_expression 1)
if(${l} STREQUAL ${lang})
list(APPEND tmp_list ${CMAKE_MATCH_1})
break()
endif()
endif()
endforeach()
if(NOT is_compile_lang_generator_expression)
list(APPEND tmp_list ${flag})
endif()
endforeach()
set(${output} ${tmp_list} PARENT_SCOPE)
endfunction()
function(convert_list_of_flags_to_string_of_flags ptr_list_of_flags string_of_flags)
# Convert the list to a string so we can do string replace
# operations on it and replace the ";" list separators with a
# whitespace so the flags are spaced out
string(REPLACE ";" " " locally_scoped_string_of_flags "${${ptr_list_of_flags}}")
# Set the output variable in the parent scope
set(${string_of_flags} ${locally_scoped_string_of_flags} PARENT_SCOPE)
endfunction()
macro(get_property_and_add_prefix result target property prefix)
get_property(target_property TARGET ${target} PROPERTY ${property})
foreach(x ${target_property})
list(APPEND ${result} ${prefix}${x})
endforeach()
endmacro()
# 1.3 generate_inc_*
# These functions are useful if there is a need to generate a file
# that can be included into the application at build time. The file
# can also be compressed automatically when embedding it.
#
# See tests/application_development/gen_inc_file for an example of
# usage.
function(generate_inc_file
source_file # The source file to be converted to hex
generated_file # The generated file
)
add_custom_command(
OUTPUT ${generated_file}
COMMAND
${PYTHON_EXECUTABLE}
$ENV{ZEPHYR_BASE}/scripts/file2hex.py
${ARGN} # Extra arguments are passed to file2hex.py
--file ${source_file}
> ${generated_file} # Does pipe redirection work on Windows?
DEPENDS ${source_file}
WORKING_DIRECTORY ${CMAKE_CURRENT_SOURCE_DIR}
)
endfunction()
function(generate_inc_file_for_target
target # The cmake target that depends on the generated file
source_file # The source file to be converted to hex
generated_file # The generated file
# Any additional arguments are passed on to file2hex.py
)
generate_inc_file(${source_file} ${generated_file} ${ARGN})
# Ensure 'generated_file' is generated before 'target' by creating a
# 'custom_target' for it and setting up a dependency between the two
# targets
# But first create a unique name for the custom target
# Replace / with _ (driver/serial => driver_serial) and . with _
set(generated_target_name ${generated_file})
string(REPLACE "/" "_" generated_target_name ${generated_target_name})
string(REPLACE "." "_" generated_target_name ${generated_target_name})
add_custom_target(${generated_target_name} DEPENDS ${generated_file})
add_dependencies(${target} ${generated_target_name})
endfunction()
# 1.2 zephyr_library_*
#
# Zephyr libraries use CMake's library concept and a set of
# assumptions about how zephyr code is organized to cut down on
# boilerplate code.
#
# A Zephyr library can be constructed by the function zephyr_library
# or zephyr_library_named. The constructors create a CMake library
# with a name accessible through the variable ZEPHYR_CURRENT_LIBRARY.
#
# The variable ZEPHYR_CURRENT_LIBRARY should seldomly be needed since
# the zephyr libraries have methods that modify the libraries. These
# methods have the signature: zephyr_library_<target-function>
#
# The methods are wrappers around the CMake target_* functions. See
# https://cmake.org/cmake/help/latest/manual/cmake-commands.7.html for
# documentation on the underlying target_* functions.
#
# The methods modify the CMake target_* API to reduce boilerplate;
# PRIVATE is assumed
# The target is assumed to be ZEPHYR_CURRENT_LIBRARY
#
# When a flag that is given through the zephyr_* API conflicts with
# the zephyr_library_* API then precedence will be given to the
# zephyr_library_* API. In other words, local configuration overrides
# global configuration.
# Constructor with a directory-inferred name
macro(zephyr_library)
zephyr_library_get_current_dir_lib_name(lib_name)
zephyr_library_named(${lib_name})
endmacro()
# Determines what the current directory's lib name would be and writes
# it to the argument "lib_name"
macro(zephyr_library_get_current_dir_lib_name lib_name)
# Remove the prefix (/home/sebo/zephyr/driver/serial/CMakeLists.txt => driver/serial/CMakeLists.txt)
file(RELATIVE_PATH name $ENV{ZEPHYR_BASE} ${CMAKE_CURRENT_LIST_FILE})
# Remove the filename (driver/serial/CMakeLists.txt => driver/serial)
get_filename_component(name ${name} DIRECTORY)
# Replace / with __ (driver/serial => driver__serial)
string(REGEX REPLACE "/" "__" name ${name})
set(${lib_name} ${name})
endmacro()
# Constructor with an explicitly given name.
macro(zephyr_library_named name)
# This is a macro because we need add_library() to be executed
# within the scope of the caller.
set(ZEPHYR_CURRENT_LIBRARY ${name})
add_library(${name} STATIC "")
zephyr_append_cmake_library(${name})
target_link_libraries(${name} zephyr_interface)
endmacro()
function(zephyr_link_interface interface)
target_link_libraries(interface INTERFACE zephyr_interface)
endfunction()
#
# zephyr_library versions of normal CMake target_<func> functions
#
function(zephyr_library_sources source)
target_sources(${ZEPHYR_CURRENT_LIBRARY} PRIVATE ${source} ${ARGN})
endfunction()
function(zephyr_library_include_directories)
target_include_directories(${ZEPHYR_CURRENT_LIBRARY} PRIVATE ${ARGN})
endfunction()
function(zephyr_library_link_libraries item)
target_link_libraries(${ZEPHYR_CURRENT_LIBRARY} ${item} ${ARGN})
endfunction()
function(zephyr_library_compile_definitions item)
target_compile_definitions(${ZEPHYR_CURRENT_LIBRARY} PRIVATE ${item} ${ARGN})
endfunction()
function(zephyr_library_compile_options item)
# The compiler is relied upon for sane behaviour when flags are in
# conflict. Compilers generally give precedence to flags given late
# on the command line. So to ensure that zephyr_library_* flags are
# placed late on the command line we create a dummy interface
# library and link with it to obtain the flags.
#
# Linking with a dummy interface library will place flags later on
# the command line than the the flags from zephyr_interface because
# zephyr_interface will be the first interface library that flags
# are taken from.
string(RANDOM random)
set(lib_name options_interface_lib_${random})
add_library( ${lib_name} INTERFACE)
target_compile_options(${lib_name} INTERFACE ${item} ${ARGN})
target_link_libraries(${ZEPHYR_CURRENT_LIBRARY} ${lib_name})
endfunction()
function(zephyr_library_cc_option)
foreach(option ${ARGV})
string(MAKE_C_IDENTIFIER check${option} check)
check_c_compiler_flag(${option} ${check})
if(${check})
zephyr_library_compile_options(${option})
endif()
endforeach()
endfunction()
# Add the existing CMake library 'library' to the global list of
# Zephyr CMake libraries. This is done automatically by the
# constructor but must called explicitly on CMake libraries that do
# not use a zephyr library constructor, but have source files that
# need to be included in the build.
function(zephyr_append_cmake_library library)
set_property(GLOBAL APPEND PROPERTY ZEPHYR_LIBS ${library})
endfunction()
########################################################
# 2. Kconfig-aware extensions
########################################################
#
# Kconfig is a configuration language developed for the Linux
# kernel. The below functions integrate CMake with Kconfig.
#
# 2.1 *_if_kconfig
#
# Functions for conditionally including directories and source files
# that have matching KConfig values.
#
# zephyr_library_sources_if_kconfig(fft.c)
# is the same as
# zephyr_library_sources_ifdef(CONFIG_FFT fft.c)
#
# add_subdirectory_if_kconfig(serial)
# is the same as
# add_subdirectory_ifdef(CONFIG_SERIAL serial)
function(add_subdirectory_if_kconfig dir)
string(TOUPPER config_${dir} UPPER_CASE_CONFIG)
add_subdirectory_ifdef(${UPPER_CASE_CONFIG} ${dir})
endfunction()
function(target_sources_if_kconfig target scope item)
get_filename_component(item_basename ${item} NAME_WE)
string(TOUPPER CONFIG_${item_basename} UPPER_CASE_CONFIG)
target_sources_ifdef(${UPPER_CASE_CONFIG} ${target} ${scope} ${item})
endfunction()
function(zephyr_library_sources_if_kconfig item)
get_filename_component(item_basename ${item} NAME_WE)
string(TOUPPER CONFIG_${item_basename} UPPER_CASE_CONFIG)
zephyr_library_sources_ifdef(${UPPER_CASE_CONFIG} ${item})
endfunction()
function(zephyr_sources_if_kconfig item)
get_filename_component(item_basename ${item} NAME_WE)
string(TOUPPER CONFIG_${item_basename} UPPER_CASE_CONFIG)
zephyr_sources_ifdef(${UPPER_CASE_CONFIG} ${item})
endfunction()
# 2.2 Misc
#
# Parse a KConfig formatted file (typically named *.config) and
# introduce all the CONF_ variables into the CMake namespace
function(import_kconfig config_file)
# Parse the lines prefixed with CONFIG_ in ${config_file}
file(
STRINGS
${config_file}
DOT_CONFIG_LIST
REGEX "^CONFIG_"
)
foreach (CONFIG ${DOT_CONFIG_LIST})
# CONFIG looks like: CONFIG_NET_BUF=y
# Match the first part, the variable name
string(REGEX MATCH "[^=]+" CONF_VARIABLE_NAME ${CONFIG})
# Match the second part, variable value
string(REGEX MATCH "=(.+$)" CONF_VARIABLE_VALUE ${CONFIG})
# The variable name match we just did included the '=' symbol. To just get the
# part on the RHS we use match group 1
set(CONF_VARIABLE_VALUE ${CMAKE_MATCH_1})
if("${CONF_VARIABLE_VALUE}" MATCHES "^\"(.*)\"$") # Is surrounded by quotes
set(CONF_VARIABLE_VALUE ${CMAKE_MATCH_1})
endif()
set("${CONF_VARIABLE_NAME}" "${CONF_VARIABLE_VALUE}" PARENT_SCOPE)
endforeach()
endfunction()
########################################################
# 3. CMake-generic extensions
########################################################
#
# These functions extend the CMake API in a way that is not particular
# to Zephyr. Primarily they work around limitations in the CMake
# language to allow cleaner build scripts.
# 3.1. *_ifdef
#
# Functions for conditionally executing CMake functions with oneliners
# e.g.
#
# if(CONFIG_FFT)
# zephyr_library_source(
# fft_32.c
# fft_utils.c
# )
# endif()
#
# Becomes
#
# zephyr_source_ifdef(
# CONFIG_FFT
# fft_32.c
# fft_utils.c
# )
#
# More Generally
# "<function-name>_ifdef(CONDITION args)"
# Becomes
# """
# if(CONDITION)
# <function-name>(args)
# endif()
# """
#
# ifdef functions are added on an as-need basis. See
# https://cmake.org/cmake/help/latest/manual/cmake-commands.7.html for
# a list of available functions.
function(add_subdirectory_ifdef feature_toggle dir)
if(${${feature_toggle}})
add_subdirectory(${dir})
endif()
endfunction()
function(target_sources_ifdef feature_toggle target scope item)
if(${${feature_toggle}})
target_sources(${target} ${scope} ${item} ${ARGN})
endif()
endfunction()
function(target_compile_definitions_ifdef feature_toggle target scope item)
if(${${feature_toggle}})
target_compile_definitions(${target} ${scope} ${item} ${ARGN})
endif()
endfunction()
function(target_include_directories_ifdef feature_toggle target scope item)
if(${${feature_toggle}})
target_include_directories(${target} ${scope} ${item} ${ARGN})
endif()
endfunction()
function(target_link_libraries_ifdef feature_toggle target item)
if(${${feature_toggle}})
target_link_libraries(${target} ${item} ${ARGN})
endif()
endfunction()
function(add_compile_option_ifdef feature_toggle option)
if(${${feature_toggle}})
add_compile_options(${option})
endif()
endfunction()
function(target_compile_option_ifdef feature_toggle target scope option)
if(${feature_toggle})
target_compile_options(${target} ${scope} ${option})
endif()
endfunction()
function(target_cc_option_ifdef feature_toggle target scope option)
if(${feature_toggle})
target_cc_option(${target} ${scope} ${option})
endif()
endfunction()
function(zephyr_library_sources_ifdef feature_toggle source)
if(${${feature_toggle}})
zephyr_library_sources(${source} ${ARGN})
endif()
endfunction()
function(zephyr_sources_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_sources(${ARGN})
endif()
endfunction()
function(zephyr_sources_ifndef feature_toggle)
if(NOT ${feature_toggle})
zephyr_sources(${ARGN})
endif()
endfunction()
function(zephyr_cc_option_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_cc_option(${ARGN})
endif()
endfunction()
function(zephyr_link_libraries_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_link_libraries(${ARGN})
endif()
endfunction()
function(zephyr_compile_options_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_compile_options(${ARGN})
endif()
endfunction()
function(zephyr_compile_definitions_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_compile_definitions(${ARGN})
endif()
endfunction()
function(zephyr_include_directories_ifdef feature_toggle)
if(${${feature_toggle}})
zephyr_include_directories(${ARGN})
endif()
endfunction()
function(zephyr_library_compile_definitions_ifdef feature_toggle item)
if(${${feature_toggle}})
zephyr_library_compile_definitions(${item} ${ARGN})
endif()
endfunction()
function(zephyr_library_compile_options_ifdef feature_toggle item)
if(${${feature_toggle}})
zephyr_library_compile_options(${item} ${ARGN})
endif()
endfunction()
function(zephyr_link_interface_ifdef feature_toggle interface)
if(${${feature_toggle}})
target_link_libraries(${interface} INTERFACE zephyr_interface)
endif()
endfunction()
function(zephyr_library_link_libraries_ifdef feature_toggle item)
if(${${feature_toggle}})
zephyr_library_link_libraries(${item})
endif()
endfunction()
macro(list_append_ifdef feature_toggle list)
if(${${feature_toggle}})
list(APPEND ${list} ${ARGN})
endif()
endmacro()
# 3.2. *_ifndef
# See 3.1 *_ifdef
function(set_ifndef variable value)
if(NOT ${variable})
set(${variable} ${value} PARENT_SCOPE)
endif()
endfunction()
function(target_cc_option_ifndef feature_toggle target scope option)
if(NOT ${feature_toggle})
target_cc_option(${target} ${scope} ${option})
endif()
endfunction()
function(zephyr_cc_option_ifndef feature_toggle)
if(NOT ${feature_toggle})
zephyr_cc_option(${ARGN})
endif()
endfunction()
function(zephyr_compile_options_ifndef feature_toggle)
if(NOT ${feature_toggle})
zephyr_compile_options(${ARGN})
endif()
endfunction()
# 3.2. *_option Compiler-compatibility checks
#
# Utility functions for silently omitting compiler flags when the
# compiler lacks support. *_cc_option was ported from KBuild, see
# cc-option in
# https://www.kernel.org/doc/Documentation/kbuild/makefiles.txt
# Writes 1 to the output variable 'ok' for the language 'lang' if
# the flag is supported, otherwise writes 0.
#
# lang must be C or CXX
#
# TODO: Support ASM
#
# Usage:
#
# check_compiler_flag(C "-Wall" my_check)
# print(my_check) # my_check is now 1
function(check_compiler_flag lang option ok)
string(MAKE_C_IDENTIFIER check${option}_${lang} ${ok})
if(${lang} STREQUAL C)
check_c_compiler_flag(${option} ${${ok}})
else()
check_cxx_compiler_flag(${option} ${${ok}})
endif()
if(${${${ok}}})
set(ret 1)
else()
set(ret 0)
endif()
set(${ok} ${ret} PARENT_SCOPE)
endfunction()
function(target_cc_option target scope option)
target_cc_option_fallback(${target} ${scope} ${option} "")
endfunction()
# Support an optional second option for when the first option is not
# supported.
function(target_cc_option_fallback target scope option1 option2)
if(CONFIG_CPLUSPLUS)
foreach(lang C CXX)
# For now, we assume that all flags that apply to C/CXX also
# apply to ASM.
check_compiler_flag(${lang} ${option1} check)
if(${check})
target_compile_options(${target} ${scope}
$<$<COMPILE_LANGUAGE:${lang}>:${option1}>
$<$<COMPILE_LANGUAGE:ASM>:${option1}>
)
elseif(option2)
target_compile_options(${target} ${scope}
$<$<COMPILE_LANGUAGE:${lang}>:${option2}>
$<$<COMPILE_LANGUAGE:ASM>:${option2}>
)
endif()
endforeach()
else()
check_compiler_flag(C ${option1} check)
if(${check})
target_compile_options(${target} ${scope} ${option1})
elseif(option2)
target_compile_options(${target} ${scope} ${option2})
endif()
endif()
endfunction()
function(target_ld_options target scope)
foreach(option ${ARGN})
string(MAKE_C_IDENTIFIER check${option} check)
check_c_compiler_flag(${option} ${check})
target_link_libraries_ifdef(${check} ${target} ${scope} ${option})
endforeach()
endfunction()
# 3.4. Debugging CMake
# Usage:
# print(BOARD)
#
# will print: "BOARD: nrf52_pca10040"
function(print arg)
message(STATUS "${arg}: ${${arg}}")
endfunction()
# Usage:
# assert(ZEPHYR_GCC_VARIANT "ZEPHYR_GCC_VARIANT not set.")
#
# will cause a FATAL_ERROR and print an error message if the first
# expression is false
macro(assert test comment)
if(NOT ${test})
message(FATAL_ERROR "Assertion failed: ${comment}")
endif()
endmacro()
# Usage:
# assert_exists(CMAKE_READELF)
#
# will cause a FATAL_ERROR if there is no file or directory behind the
# variable
macro(assert_exists var)
if(NOT EXISTS ${${var}})
message(FATAL_ERROR "No such file or directory: ${var}: '${${var}}'")
endif()
endmacro()