qt5base-lts/cmake/qt.toolchain.cmake.in
Joerg Bornemann ca59c20939 CMake: Fix usage of cache variables in qt.toolchain.cmake
We have some cache variables that are used in our qt.toolchain.cmake
toolchain file, for example QT_CHAINLOAD_TOOLCHAIN_FILE. When CMake
runs a configure test with try_compile, our toolchain file is included
again, but only a restricted set of variables is available.

Add the variables that are used in our internal toolchain file to
CMAKE_TRY_COMPILE_PLATFORM_VARIABLES. This makes them visible for
try_compile calls operating on source files.

Also pass the variables via the environment to support try_compile
calls that operate on whole projects.

Fixes: QTBUG-87873
Change-Id: Iebca9e23686bec5072194b15482e1782b9367a0e
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2020-11-05 13:04:56 +01:00

98 lines
4.4 KiB
CMake

set(__qt_toolchain_used_variables
QT_CHAINLOAD_TOOLCHAIN_FILE
QT_TOOLCHAIN_INCLUDE_FILE
QT_TOOLCHAIN_RELOCATABLE_CMAKE_DIR
QT_TOOLCHAIN_RELOCATABLE_PREFIX)
@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_qt_host_path@
@init_qt_host_path_cmake_dir@
@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}")
endif()
unset(__qt_chainload_toolchain_file)
endif()
# 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)
# 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}")
@init_qt_host_path_checks@
# 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()
# Compile tests only see a restricted set of variables.
# All cache variables, this toolchain file uses, must be made available to 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()