How to creat Qt static build as a /MT runtime library

hskoglund

Hi, for Visual Studio I'm only building for Static Release mode so I don't know about Debug mode, but for Release mode I need to add this:
set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT")

Michael418

@hskoglund Hi, thank you for your answer but set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} /MT") does not work for me. I think the problem is that some modules like QGifPlugin was not built as a /MT runtime library. Maybe some problems in pre build configurations for Qt sources before creating a static build. My CmakeLists.txt looks like this:

project(qt_app)
cmake_minimum_required(VERSION 3.8)
set(CMAKE_CXX_STANDARD 20)

set(QT_PATH "D:/Qt/6.2/msvc2022_64")
set(CMAKE_PREFIX_PATH ${QT_PATH})

add_compile_options($<$<CONFIG:Debug>:/MTd>$<$<NOT:$<CONFIG:Debug>>:/MT>) #mt

include("${QT_PATH}/lib/cmake/Qt6/Qt6Config.cmake")
include("${QT_PATH}/lib/cmake/Qt6Core/Qt6CoreConfig.cmake")
include("${QT_PATH}/lib/cmake/Qt6Widgets/Qt6WidgetsConfig.cmake")
include("${QT_PATH}/lib/cmake/Qt6Gui/Qt6GuiConfig.cmake")

set(BUILD_STATIC ON CACHE BOOL "" FORCE)
set(BUILD_SHARED_LIBS OFF CACHE BOOL "" FORCE)
set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} /Zc:__cplusplus")

if(CMAKE_SYSTEM_NAME STREQUAL "Windows")
    set(AUTOMOC_EXECUTABLE "${QT_PATH}/bin/moc.exe")
    set(AUTORCC_EXECUTABLE "${QT_PATH}/bin/rcc.exe")
elseif(CMAKE_SYSTEM_NAME STREQUAL "Linux")
    set(AUTOMOC_EXECUTABLE "${QT_PATH}/libexec/moc")
    set(AUTORCC_EXECUTABLE "${QT_PATH}/libexec/rcc")
elseif(CMAKE_SYSTEM_NAME STREQUAL "Darwin")
    set(AUTOMOC_EXECUTABLE "${QT_PATH}/libexec/moc")
    set(AUTORCC_EXECUTABLE "${QT_PATH}/libexec/rcc")
else()
    message(WARNING "CMAKE_SYSTEM_NAME is undefined")
endif()

if(NOT TARGET Qt6::moc)
    add_executable(Qt6::moc IMPORTED)
endif()
if(NOT TARGET Qt6::rcc)
    add_executable(Qt6::rcc IMPORTED)
endif()

set_target_properties(Qt6::moc PROPERTIES IMPORTED_LOCATION "${AUTOMOC_EXECUTABLE}")
set_target_properties(Qt6::rcc PROPERTIES IMPORTED_LOCATION "${AUTORCC_EXECUTABLE}")

set(Qt6Core_VERSION_MAJOR 6)
set(Qt6Core_VERSION_MINOR 2)

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_INCLUDE_CURRENT_DIR ON)

if(CMAKE_VERSION VERSION_LESS "3.7.0")
    set(CMAKE_INCLUDE_CURRENT_DIR ON)
endif()

add_executable (${PROJECT_NAME}
    mainwindow.h
    main.cpp
    mainwindow.cpp
)

target_link_libraries(${PROJECT_NAME}
    PUBLIC
    Dwrite
    Secur32
    Iphlpapi
    Winhttp
    Dnsapi
    windowsapp
    version
    userenv
    Winmm
    Wtsapi32
    Imm32
    dwmapi
    Ws2_32
    Qt6::Core
    Qt6::Widgets
    Qt6::Gui
)

target_include_directories(${PROJECT_NAME}
    PUBLIC ${QT_PATH}/include
    PUBLIC ${QT_PATH}/include/QtCore
    PUBLIC ${QT_PATH}/include/QtWidgets
    PUBLIC ${QT_PATH}/include/QtGui
)

hskoglund

I see you're on Qt 6.2.4, have you tried Qt 6.3.1?
I think for that version specifying /MT is not needed any more (when building Static MSVC versions).

Michael418

@hskoglund I have tried recently Qt 6.3.1 with the same configure parameters for the build that I mentioned in the description, and I got the same issues.

DerReisende

@Michael418 Have you tried building just the static release version? That should succeed. I couldn't get a mixed build to work as well AFAIK you need to specify /MTd for debug builds.

I used shared debug version and just built my app with static release.

SimonSchroeder

The error messages tell that you are compiling your code with parameters normally used for release, but link to the Qt debug libraries. Are you compiling a debug or release version of your software? If you are compiling a debug version you should use /MTd instead of /MT like the Qt libraries do. If you are compiling a release version we need to figure out why it links to the debug version. Which of the two is it?

Michael418

@DerReisende @SimonSchroeder thanks, building just the static release version fixed the problem of compiling. However, exe file still has dependencies from windows DLL files but I need to make a static executable file that can be run on any machine. Is there a way to avoid such dependencies?

UxTheme.dll
DWrite.dll
dwmapi.dll
GDI32.dll
IMM32.dll
OLEAUT32.dll
WTSAPI32.dll
api-ms-win-core-synch-l1-2-0.dll
USERENV.dll
ADVAPI32.dll
KERNEL32.dll
NETAPI32.dll
ole32.dll
SHELL32.dll
USER32.dll
VERSION.dll
WINMM.dll
WS2_32.dll
api-ms-win-core-winrt-error-l1-1-0.dll
api-ms-win-core-winrt-l1-1-0.dll
api-ms-win-core-winrt-error-l1-1-1.dll
api-ms-win-core-winrt-string-l1-1-0.dll

JonB

@Michael418
So far as I know (unless a Windows expert corrects me) these are all (subject to verification for some?) Windows System files. They must be present on the target machine as part of Windows, there is no "static" version of these.

DerReisende

@Michael418 You cannot avoid dependencies to windows system dlls.
There is a reason why qt has a minimum OS requirement.

Michael418

@DerReisende Is there official information that Qt requires specific DLLs from Windows? I just need proof for my project if I can not avoid some DDLs.

JonB

@Michael418 said in How to creat Qt static build as a /MT runtime library:

Is there official information that Qt requires specific DLLs from Windows?

No. And btw this is not a Qt-specific restriction, it's Windows.