qt5base-lts/cmake/qt.toolchain.cmake.in
Alexandru Croitor b04a0f0c04 CMake: Allow enabling/disabling QT_HOST_PATH checks via variable
One can now pass -DQT_REQUIRE_HOST_PATH_CHECK=OFF or
-DQT_REQUIRE_HOST_PATH_CHECK=ON to force disable or enable
the QT_HOST_PATH and QT_HOST_CMAKE_DIR_PATH validity checks.

One potential use case is if a project wants to manually find
QtFooTools packages by manipulating CMAKE_FIND_ROOT_PATH and such,
in which case they might not want to pass a QT_HOST_PATH.

Another potential use case is cross-building Qt with
-DQT_BUILD_TOOLS_WHEN_CROSSCOMPILING=ON and allowing the same
generated toolchain file to be used on the device image.

By default the generated toolchain file would require a host path
because it expects that it's still being used for cross-compiling.
But once the toolchain file is deployed to the device there's no need
to use the host tools anymore.

Another use case is building a desktop Qt using the host tools of
another desktop Qt. The new desktop Qt can use its newly built tools
just fine and wouldn't need the original desktop Qt tools.

QT_REQUIRE_HOST_PATH_CHECK needs to be added the list of vars to pass
through to try_compile calls.

Change-Id: I4b922b5d854828e6b9210dd8c07b4b1b8630aad1
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Craig Scott <craig.scott@qt.io>
2021-10-29 15:34:12 +02:00

214 lines
9.6 KiB
CMake

set(__qt_toolchain_used_variables
QT_CHAINLOAD_TOOLCHAIN_FILE
QT_TOOLCHAIN_INCLUDE_FILE
QT_TOOLCHAIN_RELOCATABLE_CMAKE_DIR
QT_TOOLCHAIN_RELOCATABLE_PREFIX
QT_HOST_PATH
QT_HOST_PATH_CMAKE_DIR
QT_REQUIRE_HOST_PATH_CHECK
)
@init_additional_used_variables@
# Make cache variables used by this toolchain file available to the
# try_compile command that operates on sources files.
list(APPEND CMAKE_TRY_COMPILE_PLATFORM_VARIABLES ${__qt_toolchain_used_variables})
list(REMOVE_DUPLICATES CMAKE_TRY_COMPILE_PLATFORM_VARIABLES)
# Turn the environment variables that are created at the end of this
# file into proper variables. This is needed for try_compile calls
# that operate on whole projects.
if($ENV{_QT_TOOLCHAIN_VARS_INITIALIZED})
foreach(var ${__qt_toolchain_used_variables})
set(${var} "$ENV{_QT_TOOLCHAIN_${var}}")
endforeach()
endif()
@init_original_toolchain_file@
@init_vcpkg@
@init_platform@
if(NOT "${QT_CHAINLOAD_TOOLCHAIN_FILE}" STREQUAL "")
set(__qt_chainload_toolchain_file "${QT_CHAINLOAD_TOOLCHAIN_FILE}")
endif()
if(__qt_chainload_toolchain_file)
get_filename_component(__qt_chainload_toolchain_file_real_path
"${__qt_chainload_toolchain_file}" REALPATH)
if(__qt_chainload_toolchain_file_real_path STREQUAL CMAKE_CURRENT_LIST_FILE)
message(FATAL_ERROR
"Woah, the Qt toolchain file tried to include itself recusively! '${__qt_chainload_toolchain_file}' "
"Make sure to remove qtbase/CMakeCache.txt and reconfigure qtbase with 'cmake' "
"rather than 'qt-cmake', and then you can reconfigure your own project."
)
elseif(NOT EXISTS "${__qt_chainload_toolchain_file_real_path}")
message(WARNING "The toolchain file to be chainloaded "
"'${__qt_chainload_toolchain_file}' does not exist.")
else()
include("${__qt_chainload_toolchain_file}")
set(__qt_chainload_toolchain_file_included TRUE)
endif()
unset(__qt_chainload_toolchain_file)
endif()
@init_post_chainload_toolchain@
# Compute dynamically the Qt installation prefix from the location of this file. This allows
# the usage of the toolchain file when the Qt installation is relocated.
get_filename_component(QT_TOOLCHAIN_RELOCATABLE_INSTALL_PREFIX
${CMAKE_CURRENT_LIST_DIR}/../@qt_path_from_cmake_config_dir_to_prefix@
ABSOLUTE)
# Compute the path to the installed Qt lib/cmake folder.
# We assume that the Qt toolchain location is inside the CMake Qt6 package, and thus the directory
# one level higher is what we're looking for.
get_filename_component(QT_TOOLCHAIN_RELOCATABLE_CMAKE_DIR "${CMAKE_CURRENT_LIST_DIR}/.." ABSOLUTE)
# REROOT_PATH_ISSUE_MARKER
# There's a subdirectory check in cmake's cmFindCommon::RerootPaths() function, that doesn't handle
# the case of CMAKE_PREFIX_PATH == CMAKE_FIND_ROOT_PATH for a particular pair of entries.
# Instead of collapsing the search prefix (which is the case when one is a subdir of the other),
# it concatenates them creating an invalid path. Workaround it by setting the root path to the
# Qt install prefix, and the prefix path to the lib/cmake subdir.
list(PREPEND CMAKE_PREFIX_PATH "${QT_TOOLCHAIN_RELOCATABLE_CMAKE_DIR}")
list(PREPEND CMAKE_FIND_ROOT_PATH "${QT_TOOLCHAIN_RELOCATABLE_INSTALL_PREFIX}")
# Let CMake load our custom platform modules.
# CMake-provided platform modules take precedence.
if(NOT QT_AVOID_CUSTOM_PLATFORM_MODULES)
list(PREPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_LIST_DIR}/platforms")
endif()
# Handle packages located in QT_ADDITIONAL_PACKAGES_PREFIX_PATH when cross-compiling. Needed for
# Conan.
# We prepend to CMAKE_PREFIX_PATH so that a find_package(Qt6Foo) call works, without having to go
# through the Qt6 umbrella package. The paths must end in lib/cmake to esnsure the package is found.
# See REROOT_PATH_ISSUE_MARKER.
# We prepend to CMAKE_FIND_ROOT_PATH, due to the bug mentioned at REROOT_PATH_ISSUE_MARKER.
set(__qt_toolchain_additional_packages_prefixes "")
if(QT_ADDITIONAL_PACKAGES_PREFIX_PATH)
list(APPEND __qt_toolchain_additional_packages_prefixes
${QT_ADDITIONAL_PACKAGES_PREFIX_PATH})
endif()
if(DEFINED ENV{QT_ADDITIONAL_PACKAGES_PREFIX_PATH}
AND NOT "$ENV{QT_ADDITIONAL_PACKAGES_PREFIX_PATH}" STREQUAL "")
list(APPEND __qt_toolchain_additional_packages_prefixes
$ENV{QT_ADDITIONAL_PACKAGES_PREFIX_PATH})
endif()
if(__qt_toolchain_additional_packages_prefixes)
set(__qt_toolchain_additional_packages_root_paths "")
set(__qt_toolchain_additional_packages_prefix_paths "")
foreach(__qt_additional_path IN LISTS __qt_toolchain_additional_packages_prefixes)
file(TO_CMAKE_PATH "${__qt_additional_path}" __qt_additional_path)
get_filename_component(__qt_additional_path "${__qt_additional_path}" ABSOLUTE)
set(__qt_additional_path_lib_cmake "${__qt_additional_path}")
if(NOT __qt_additional_path_lib_cmake MATCHES "/lib/cmake$")
string(APPEND __qt_additional_path_lib_cmake "/lib/cmake")
endif()
list(APPEND __qt_toolchain_additional_packages_root_paths
"${__qt_additional_path}")
list(APPEND __qt_toolchain_additional_packages_prefix_paths
"${__qt_additional_path_lib_cmake}")
endforeach()
list(PREPEND CMAKE_PREFIX_PATH ${__qt_toolchain_additional_packages_prefix_paths})
list(PREPEND CMAKE_FIND_ROOT_PATH ${__qt_toolchain_additional_packages_root_paths})
unset(__qt_additional_path)
unset(__qt_additional_path_lib_cmake)
unset(__qt_toolchain_additional_packages_root_paths)
unset(__qt_toolchain_additional_packages_prefix_paths)
endif()
unset(__qt_toolchain_additional_packages_prefixes)
# Allow customization of the toolchain file by placing an additional file next to it.
set(__qt_toolchain_extra_file "${CMAKE_CURRENT_LIST_DIR}/qt.toolchain.extra.cmake")
if(EXISTS "${__qt_toolchain_extra_file}")
include("${__qt_toolchain_extra_file}")
endif()
# Allow customization of the toolchain file by passing a path to an additional CMake file to be
# included.
if(QT_TOOLCHAIN_INCLUDE_FILE)
get_filename_component(__qt_toolchain_include_file_real_path
"${QT_TOOLCHAIN_INCLUDE_FILE}" REALPATH)
if(EXISTS "${__qt_toolchain_include_file_real_path}")
include("${__qt_toolchain_include_file_real_path}")
else()
message(WARNING "The passed extra toolchain file to be included does not exist: "
"${__qt_toolchain_include_file_real_path}")
endif()
endif()
# Set up QT_HOST_PATH and do sanity checks.
# A host path is required when cross-compiling but optional when doing a native build.
# Requiredness can be overridden via variable.
if(DEFINED QT_REQUIRE_HOST_PATH_CHECK)
set(__qt_toolchain_host_path_required "${QT_REQUIRE_HOST_PATH_CHECK}")
else()
set(__qt_toolchain_host_path_required "@qt_host_path_required@")
endif()
set(__qt_toolchain_initial_qt_host_path
"@qt_host_path_absolute@")
set(__qt_toolchain_initial_qt_host_path_cmake_dir
"@qt_host_path_cmake_dir_absolute@")
# Prefer initially configured path if none was explicitly set.
if(NOT DEFINED QT_HOST_PATH AND __qt_toolchain_initial_qt_host_path
AND EXISTS "${__qt_toolchain_initial_qt_host_path}")
set(QT_HOST_PATH "${__qt_toolchain_initial_qt_host_path}" CACHE PATH "")
endif()
if(NOT QT_HOST_PATH STREQUAL "")
get_filename_component(__qt_toolchain_host_path_absolute "${QT_HOST_PATH}" ABSOLUTE)
endif()
if(__qt_toolchain_host_path_required AND
("${QT_HOST_PATH}" STREQUAL "" OR NOT EXISTS "${__qt_toolchain_host_path_absolute}"))
message(FATAL_ERROR
"To use a cross-compiled Qt, please set the QT_HOST_PATH cache variable to the location "
"of your host Qt installation.")
endif()
# QT_HOST_PATH_CMAKE_DIR is needed to work around the rerooting issue when looking for host tools
# See REROOT_PATH_ISSUE_MARKER.
# Prefer initially configured path if none was explicitly set.
if(__qt_toolchain_host_path_required AND NOT DEFINED QT_HOST_PATH_CMAKE_DIR)
if(__qt_toolchain_initial_qt_host_path_cmake_dir
AND EXISTS "${__qt_toolchain_initial_qt_host_path_cmake_dir}")
set(QT_HOST_PATH_CMAKE_DIR "${__qt_toolchain_initial_qt_host_path_cmake_dir}" CACHE PATH "")
else()
# First try to auto-compute the location instead of requiring to set QT_HOST_PATH_CMAKE_DIR
# explicitly.
set(__qt_candidate_host_path_cmake_dir "${QT_HOST_PATH}/lib/cmake")
if(__qt_candidate_host_path_cmake_dir AND EXISTS "${__qt_candidate_host_path_cmake_dir}")
set(QT_HOST_PATH_CMAKE_DIR
"${__qt_candidate_host_path_cmake_dir}" CACHE PATH "")
endif()
endif()
endif()
if(NOT QT_HOST_PATH_CMAKE_DIR STREQUAL "")
get_filename_component(__qt_toolchain_host_path_cmake_dir_absolute
"${QT_HOST_PATH_CMAKE_DIR}" ABSOLUTE)
endif()
if(__qt_toolchain_host_path_required AND
("${QT_HOST_PATH_CMAKE_DIR}" STREQUAL ""
OR NOT EXISTS "${__qt_toolchain_host_path_cmake_dir_absolute}"))
message(FATAL_ERROR
"To use a cross-compiled Qt, please set the QT_HOST_PATH_CMAKE_DIR cache variable to "
"the location of your host Qt installation lib/cmake directory.")
endif()
# Compile tests only see a restricted set of variables.
# All cache variables, this toolchain file uses, must be made available to project-based
# try_compile tests because this toolchain file will be included there too.
if(NOT "$ENV{_QT_TOOLCHAIN_VARS_INITIALIZED}")
set(ENV{_QT_TOOLCHAIN_VARS_INITIALIZED} ON)
foreach(var ${__qt_toolchain_used_variables})
set(ENV{_QT_TOOLCHAIN_${var}} "${${var}}")
endforeach()
endif()