zephyr/cmake/modules/user_cache.cmake

99 lines
3.0 KiB
CMake

# SPDX-License-Identifier: Apache-2.0
#
# Copyright (c) 2021, Nordic Semiconductor ASA
# Configure user cache directory.
#
# The user cache can be used for caching of data that should be persistent
# across builds to speed up CMake configure / build system generation and/or
# compilation.
#
# Only data that can be safely re-generated should be placed in this cache.
#
# Zephyr build system uses this user cache to store Zephyr compiler check
# results which significantly improve toolchain testing performance.
# See https://github.com/zephyrproject-rtos/zephyr/pull/7102 for details.
#
# Outcome:
# The following variables will be defined when this CMake module completes:
#
# - USER_CACHE_DIR: User cache directory in use.
#
# If the above variable is already set when this CMake module is loaded,
# then no changes to the variable will happen.
#
# Variables set by this module and not mentioned above are considered internal
# use only and may be removed, renamed, or re-purposed without prior notice.
include_guard(GLOBAL)
include(python)
function(find_appropriate_cache_directory dir)
set(env_suffix_LOCALAPPDATA .cache)
if(CMAKE_HOST_APPLE)
# On macOS, ~/Library/Caches is the preferred cache directory.
set(env_suffix_HOME Library/Caches)
else()
set(env_suffix_HOME .cache)
endif()
# Determine which env vars should be checked
if(CMAKE_HOST_APPLE)
set(dirs HOME)
elseif(CMAKE_HOST_WIN32)
set(dirs LOCALAPPDATA)
else()
# Assume Linux when we did not detect 'mac' or 'win'
#
# On Linux, freedesktop.org recommends using $XDG_CACHE_HOME if
# that is defined and defaulting to $HOME/.cache otherwise.
set(dirs
XDG_CACHE_HOME
HOME
)
endif()
foreach(env_var ${dirs})
if(DEFINED ENV{${env_var}})
set(env_dir $ENV{${env_var}})
set(test_user_dir ${env_dir}/${env_suffix_${env_var}})
execute_process(COMMAND ${PYTHON_EXECUTABLE}
${ZEPHYR_BASE}/scripts/build/dir_is_writeable.py ${test_user_dir}
RESULT_VARIABLE writable_result
)
if("${writable_result}" STREQUAL "0")
# The directory is write-able
set(user_dir ${test_user_dir})
break()
else()
# The directory was not writeable, keep looking for a suitable
# directory
endif()
endif()
endforeach()
# Populate local_dir with a suitable directory for caching
# files. Prefer a directory outside of the git repository because it
# is good practice to have clean git repositories.
if(DEFINED user_dir)
# Zephyr's cache files go in the "zephyr" subdirectory of the
# user's cache directory.
set(local_dir ${user_dir}/zephyr)
else()
set(local_dir ${ZEPHYR_BASE}/.cache)
endif()
set(${dir} ${local_dir} PARENT_SCOPE)
endfunction()
# Populate USER_CACHE_DIR with a directory that user applications may
# write cache files to.
if(NOT DEFINED USER_CACHE_DIR)
find_appropriate_cache_directory(USER_CACHE_DIR)
endif()
message(STATUS "Cache files will be written to: ${USER_CACHE_DIR}")