Unable to compile using Mingwx64 on windows, Command line option error

Dariusz

Hey

It seems to me like Qt configuration for mingw is somehow broken and it adds command lines to cmake & cause mingw to go bananas.

Some other peron has the same error here > https://stackoverflow.com/questions/67824944/unrecognized-command-line-option-zc-cplusplus-and-unrecognized-command-line

I'm on Clion & Mingwxt64 qt 6.1.2

Problems were encountered while collecting compiler information:
	c++.exe: error: unrecognized command line option '-Zc:__cplusplus'
	c++.exe: error: unrecognized command line option '-permissive-'; did you mean '-fpermissive'?

Can any1 hint out on how can I fix this?

VRonin

Are you trying to compile your project or the Qt library itself?
Can you post your CMakeLists?

Dariusz

@VRonin Hey I've simply changed my compiler from msvc to mingw64. Im trying to run my app. Using precompiled mingw64 binaries from qt installer. I tried using both mingw shipped ith QT, and latest official one. Both have issues

Here is most of my Qt related cmake code > it currently "has issues" with dlls given some of them don't exist under mingw, but thats to fix after I get it to build without the darn error :- (

set(sp "-----  ")
set(QT_PATH "C:/Qt/6.1.2/")
if (MSVC)
    # warning level 4 and all warnings as errors
    #add_compile_options(/W4 /WX)
    set(QT_PATH ${QT_PATH}msvc2019_64)
    message(\n ${sp} "IM IN MSVC")
else ()
    # lots of warnings and all warnings as errors
    message(\n ${sp} "IM NOT IN MSVC")
    #add_compile_options(-Wall -Wextra -pedantic -Werror)
    add_compile_options(-Wno-error=unknown-warning)
    #set(CMAKE_SHARED_LIBRARY_LINK_C_FLAGS "")
    #set(CMAKE_SHARED_LIBRARY_LINK_CXX_FLAGS "")
    #set(CMAKE_C_COMPILER_WORKS 1)
    set(QT_PATH ${QT_PATH}mingw81_64)
endif ()



set(CMAKE_PREFIX_PATH ${CMAKE_PREFIX_PATH} ${QT_PATH})

set(LIB_MODE STATIC)
set(GLOBAL_ROOT ${CMAKE_SOURCE_DIR})

set(CMAKE_AUTOMOC ON)
set(CMAKE_AUTORCC ON)
set(CMAKE_AUTOUIC ON)

set(QT_USE_QTGUI TRUE)
set(QT_USE_QTXML TRUE)

set(QT_VERSION 6)
set(REQUIRED_LIBS Core Widgets Gui Network OpenGL)
set(REQUIRED_LIBS_QUALIFIED Qt6::Core Qt6::Widgets Qt6::Gui Qt6::Network Qt6::OpenGL)
ADD_DEFINITIONS(-DQT_NO_KEYWORDS)
ADD_DEFINITIONS(${QT_DEFINITIONS} -DQT_MESSAGELOGCONTEXT)
ADD_DEFINITIONS(-D_USE_MATH_DEFINES)

message("\n\n")
message(${sp} "CORE CMAKE IMPORT")
message(${sp} "Global Root : " ${GLOBAL_ROOT})
message(${sp} "QT          : " ${QT_PATH})
message(${sp} "")
message(${sp} "FindPackage QT : " "Qt${QT_VERSION}" " COMPONENTS : " "${REQUIRED_LIBS} " "REQUIRED")
message("\n\n")

find_package(Qt${QT_VERSION} COMPONENTS ${REQUIRED_LIBS} REQUIRED)


message(\n\n ${sp} "Qt Prep\n")
# Import QT dlls/etc
if (WIN32)
    set(DEBUG_SUFFIX)
    if (CMAKE_BUILD_TYPE MATCHES "Debug")
        set(DEBUG_SUFFIX "d")
    endif ()
    set(QT_PATH ${CMAKE_PREFIX_PATH})
    message(${sp} "DEBUG_SUFFIX " ${DEBUG_SUFFIX})
    if (EXISTS "${QT_PATH}/bin")
        file(MAKE_DIRECTORY "${GLOBAL_ROOT}/libOutput/test/plugins/platforms")
        file(MAKE_DIRECTORY "${GLOBAL_ROOT}/libOutput/plugins/platforms")
        file(COPY "${QT_PATH}/plugins/platforms/qwindows${DEBUG_SUFFIX}.dll" DESTINATION "${GLOBAL_ROOT}/libOutput/plugins/platforms")
        file(COPY "${QT_PATH}/plugins/platforms/qwindows${DEBUG_SUFFIX}.dll" DESTINATION "${GLOBAL_ROOT}/libOutput/test/plugins/platforms")
        file(COPY "${QT_PATH}/plugins/platforms/qwindows${DEBUG_SUFFIX}.pdb" DESTINATION "${GLOBAL_ROOT}/libOutput/plugins/platforms")
        file(COPY "${QT_PATH}/plugins/platforms/qwindows${DEBUG_SUFFIX}.pdb" DESTINATION "${GLOBAL_ROOT}/libOutput/test/plugins/platforms")
        foreach (QT_LIB ${REQUIRED_LIBS})
            set(filePath ${QT_PATH}/bin/Qt${QT_VERSION}${QT_LIB}${DEBUG_SUFFIX}.dll)
            get_filename_component(barename ${filePath} NAME)
            if (NOT EXISTS "${GLOBAL_ROOT}/libOutput/test/${barename}")
                message(${sp} "Copying file : " ${QT_PATH}/bin/Qt${QT_VERSION}${QT_LIB}${DEBUG_SUFFIX}.dll to Tests)
                file(COPY "${filePath}" DESTINATION "${GLOBAL_ROOT}/libOutput/test")
            elseif (NOT EXISTS "${GLOBAL_ROOT}/libOutput/${barename}")
                message(${sp} "Copying file : " ${QT_PATH}/bin/Qt${QT_VERSION}${QT_LIB}${DEBUG_SUFFIX}.dll to Root)
                file(COPY "${filePath}" DESTINATION "${GLOBAL_ROOT}/libOutput/")
            else ()
                message(${sp} "Skipping copying of ${barename}")
            endif ()
        endforeach (QT_LIB)

    else ()
        message(${sp} WARNING " COULD NOT FIND QT LIBS! ")
    endif ()
endif ()

VRonin

My eyes are burning! especially the # Import QT dlls/etc part.
There is no add_library/add_executable here so I have no clue what that CMakeLists is doing

Christian Ehrlicher

Also you can't simply switch the compiler - you need the correct Qt for it. -Zc:__cplusplus is a msvc option.

Dariusz

@VRonin Hahahha I know :d I'm in process of slowly... learning to update it.

This part essentially copies all qt dlls I need into the exe location of my app

The add_executable(${PROJECT_NAME} ${SRC}) is just that < There is nothing else that I do

I forgot to add the link part to the code above which is >

#### QT
function(linkQTLibs)
    target_link_libraries(${PROJECT_NAME}
            ${REQUIRED_LIBS_QUALIFIED}
            )
endfunction()

But after that its zip.

Esentially its

Cmake:

project(Hello world)
set(CMAKE_CXX_STANDARD 20)

include("pathToCmake/CmakeList.txt") # Which is the one posted in previous post 
set(SRC main.cpp)
add_executable(${PROJECT_NAME} ${SRC})
linkQTLibs()

And that's it.

I don't set any more flags/etc. Its rather "simple" build.

Dariusz

@Christian-Ehrlicher In the cmake post above there is (clean up now) >

set(QT_PATH "C:/Qt/6.1.2/")
if (MSVC)
    set(QT_PATH ${QT_PATH}msvc2019_64)
else ()
    set(QT_PATH ${QT_PATH}mingw81_64)
endif ()

This essentially " for now" set correct QT version for either MSVC or Mingw, In future I'll handle mac/arm/etc. But for now basics.

So what I end up is, mingw as my toolchain and QT from mingw folder using either qt-mingw bundled compiler or program files/official one. Both fail.

Christian Ehrlicher

I can only tell you what I see - you somewhere mixing up MinGW and MSVC - you're using a MinGW compiler but your Qt thinks it's MSVC.

Dariusz

@Christian-Ehrlicher Yeh, its... difficult. I think I don't know to "properly" set an explicit path to a specific qt version... what would be the cmake command for it ?

VRonin

@Dariusz said in Unable to compile using Mingwx64 on windows, Command line option error:

what would be the cmake command for it ?

There shouldn't be one. Do not set it in CMakeLists.txt

The idea is that find_package should be able to find it. There are 2 ways to do this:

have the Qt path in your PATH
- this is what you normally do on the command line, call qtenv2.bat from the Qt bin folder and it will set up your environment so that find_package will work
add the Qt path to CMAKE_PREFIX_PATH
- this is what Qt Creator does automatically when you configure the Kit

Dariusz

@VRonin said in Unable to compile using Mingwx64 on windows, Command line option error:

@Dariusz said in Unable to compile using Mingwx64 on windows, Command line option error:

what would be the cmake command for it ?

There shouldn't be one. Do not set it in CMakeLists.txt

The idea is that find_package should be able to find it. There are 2 ways to do this:

have the Qt path in your PATH

this is what you normally do on the command line, call qtenv2.bat from the Qt bin folder and it will set up your environment so that find_package will work

add the Qt path to CMAKE_PREFIX_PATH

this is what Qt Creator does automatically when you configure the Kit

I dont want path/environemnt based Qt library. I have many projects each of which require specific qt to be run on/tested on. The idea of having to edit path every time I change projects is quite... bad. So I need to set qt via code & copy dlls manually as far as I can tell.

The idea that there will be only 1 qt version on the system is quite... frustrating to me.

VRonin

@Dariusz said in Unable to compile using Mingwx64 on windows, Command line option error:

The idea that there will be only 1 qt version on the system is quite... frustrating to me.

There isn't. I have 4 versions on my machine (5.5, 5.15, 6.1, dev). I don't know CLion but I'm sure there is a way to set CMAKE_PREFIX_PATH before it runs CMake, see https://stackoverflow.com/questions/54444846/equivalent-of-cmake-prefix-path-in-clion
Set it to C:/Qt/6.1.2/mingw81_64 and remove the set(QT_PATH

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Unable to compile using Mingwx64 on windows, Command line option error