qt5base-lts/CMakeLists.txt
Craig Scott d97fd7af2b Build examples in isolated sub-builds using ExternalProject
Examples are intended to show how to build against an installed Qt.
Building them as part of the main build means the way the Qt targets
are defined and created are not representative of an end user's build.
By building them as separate projects using ExternalProject, we can
more closely replicate the intended audience's environment. This
should allow us to catch more problems earlier.

Having examples built as part of the main build also creates problems
with some static builds where a tool built by the main build is needed
during configure time. This happens with other repos like qtdeclarative
but not (currently) with qtbase. Converting the examples in qtbase to
be built using ExternalProject is intended as a demonstrator for how
other repos can do similar. Until other repos are converted, they will
continue to work as they did before, with examples as part of the main
build for non-static builds only.

The new build-externally behavior is only supported for non-prefix
builds with this change. Prefix builds will continue to use the old
non-external method. Support for building examples externally in
prefix builds will be a separate change.

Task-number: QTBUG-90820
Fixes: QTBUG-91068
Change-Id: I2304329940568dbdb7da18d54d5595ea7d8668bc
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-05-26 13:33:29 +02:00

173 lines
6.6 KiB
CMake

# special case skip regeneration
# Need an explicit call at the top level. This is the absolute minimum version
# needed to configure the project with any combination of enabled features.
# The call to qt_build_repo_begin() will upgrade policies further.
cmake_minimum_required(VERSION 3.16)
# Get the repo version and CMake policy details
include(.cmake.conf)
# Bail out if any part of the build directory's path is symlinked.
# The OS-level current working directory is always the real path and some
# parts of the build system only deal with that path, which causes confusion
# when compared to the logical working directory maintained by the shell and
# passed on the command line.
get_filename_component(build_dir_absolute "${CMAKE_BINARY_DIR}" ABSOLUTE)
get_filename_component(build_dir_realpath "${CMAKE_BINARY_DIR}" REALPATH)
if(NOT build_dir_absolute STREQUAL build_dir_realpath)
message(FATAL_ERROR "The build path \"${CMAKE_BINARY_DIR}\" contains symlinks. \
This is not supported. Possible solutions:
- map directories using a transparent mechanism such as mount --bind
- pass the real path of the build directory to CMake, e.g. using \
cd $(realpath <build_dir>) before invoking cmake <source_dir>.")
endif()
unset(build_dir_absolute)
unset(build_dir_realpath)
# Early check to reduce chance of warning being lost in the output
include("${CMAKE_CURRENT_SOURCE_DIR}/cmake/QtCMakeVersionHelpers.cmake")
qt_internal_check_for_suitable_cmake_version()
# Run auto detection routines, but not when doing standalone tests. In that case, the detection
# results are taken from either QtBuildInternals or the qt.toolchain.cmake file. Also, inhibit
# auto-detection in a top-level build, because the top-level project file already includes it.
if(NOT QT_BUILD_STANDALONE_TESTS AND NOT QT_SUPERBUILD)
include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/QtAutoDetect.cmake)
endif()
project(QtBase
VERSION "${QT_REPO_MODULE_VERSION}"
DESCRIPTION "Qt Base Libraries"
HOMEPAGE_URL "https://qt.io/"
LANGUAGES CXX C ASM
)
# Make sure we only use latest private CMake API, aka no compatibility wrappers.
set(QT_NO_INTERNAL_COMPATIBILITY_FUNCTIONS TRUE)
# Make sure we use the fixed BASE argument of qt_add_resource.
set(QT_USE_FIXED_QT_ADD_RESOURCE_BASE TRUE)
if(NOT QT_BUILD_STANDALONE_TESTS)
## Add some paths to check for cmake modules:
list(PREPEND CMAKE_MODULE_PATH
"${CMAKE_CURRENT_SOURCE_DIR}/cmake"
"${CMAKE_CURRENT_SOURCE_DIR}/cmake/3rdparty/extra-cmake-modules/find-modules"
"${CMAKE_CURRENT_SOURCE_DIR}/cmake/3rdparty/kwin"
)
if(MACOS)
# Add module directory to pick up custom Info.plist template
list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/macos")
elseif(IOS)
# Add module directory to pick up custom Info.plist template
list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/cmake/ios")
endif()
## Find the build internals package.
set(QT_BUILD_INTERNALS_SKIP_CMAKE_MODULE_PATH_ADDITION TRUE)
list(PREPEND CMAKE_PREFIX_PATH
"${CMAKE_CURRENT_SOURCE_DIR}/cmake"
)
find_package(QtBuildInternals CMAKE_FIND_ROOT_PATH_BOTH)
unset(QT_BUILD_INTERNALS_SKIP_CMAKE_MODULE_PATH_ADDITION)
else()
# When building standalone tests, an istalled BuildInternals package already exists.
find_package(Qt6 REQUIRED COMPONENTS BuildInternals CMAKE_FIND_ROOT_PATH_BOTH)
endif()
qt_build_repo_begin()
if(NOT QT_BUILD_STANDALONE_TESTS)
## Should this Qt be static or dynamically linked?
option(BUILD_SHARED_LIBS "Build Qt statically or dynamically" ON)
set(QT_BUILD_SHARED_LIBS ${BUILD_SHARED_LIBS})
# This variable is also set in Qt6CoreConfigExtras.cmake, but it's not loaded when building
# qtbase. Set it here so qt_add_plugin can compute the proper plugin flavor.
set(QT6_IS_SHARED_LIBS_BUILD ${BUILD_SHARED_LIBS})
## Should this Qt be built with Werror?
option(WARNINGS_ARE_ERRORS "Build Qt with warnings as errors" ${FEATURE_developer_build})
## Should this Qt create versioned hard link for some tools?
option(QT_CREATE_VERSIONED_HARD_LINK "Enable the use of versioned hard link" ON)
## QtBase specific configure tests:
include(QtBaseConfigureTests)
## Build System tests:
include(QtBaseCMakeTesting)
## Targets for global features, etc.:
include(QtBaseGlobalTargets)
## Set language standards after QtBaseGlobalTargets, because that's when the relevant
## feature variables are available.
qt_set_language_standards()
#include CoreMacros() for qt6_generate_meta_types()
set(QT_DEFAULT_MAJOR_VERSION 6)
include(src/corelib/Qt6CoreMacros.cmake)
# Needed when building qtbase for android.
include(src/corelib/Qt6AndroidMacros.cmake)
if(WASM)
# Needed when building for WebAssembly.
include(cmake/QtWasmHelpers.cmake)
qt_internal_setup_wasm_target_properties(Platform)
endif()
# Set up optimization flags like in qmake.
# This function must be called after the global QT_FEATURE_xxx variables have been set up,
# aka after QtBaseGlobalTargets is processed.
# It also has to be called /before/ adding add_subdirectory(src), so that per-directory
# modifications can still be applied if necessary (like in done in Core and Gui).
qt_internal_set_up_config_optimizations_like_in_qmake()
## Setup documentation
add_subdirectory(doc)
## Visit all the directories:
add_subdirectory(src)
endif()
if(QT_BUILD_TESTS)
add_subdirectory(tests)
if(NOT QT_BUILD_TESTS_BY_DEFAULT)
set_property(DIRECTORY tests PROPERTY EXCLUDE_FROM_ALL TRUE)
endif()
endif()
if(NOT QT_BUILD_STANDALONE_TESTS)
if(QT_WILL_BUILD_TOOLS AND QT_FEATURE_settings)
add_subdirectory(qmake)
endif()
# As long as we use the mkspecs (for qplatformdefs.h), we need to always
# install it, especially when cross-compiling.
set(mkspecs_install_dir "${INSTALL_MKSPECSDIR}")
qt_path_join(mkspecs_install_dir ${QT_INSTALL_DIR} ${mkspecs_install_dir})
file(GLOB mkspecs_subdirs
LIST_DIRECTORIES TRUE
"${PROJECT_SOURCE_DIR}/mkspecs/*")
foreach(entry IN LISTS mkspecs_subdirs)
if (IS_DIRECTORY ${entry})
qt_copy_or_install(DIRECTORY "${entry}"
DESTINATION ${mkspecs_install_dir}
USE_SOURCE_PERMISSIONS)
else()
qt_copy_or_install(FILES "${entry}"
DESTINATION ${mkspecs_install_dir})
endif()
endforeach()
endif()
qt_build_repo_end()
if(NOT QT_BUILD_STANDALONE_TESTS AND QT_BUILD_EXAMPLES)
add_subdirectory(examples)
endif()