Qt5 and Cmake : strange behavior with wrapp_ui/cpp

BrigitteLPB

Hi,
I try to set up a cmake project for Qt5. In fact it works but not as I want.
This is a example of my test project

My project folder
┣CMakelists.txt (root)
┗src (folder)
   ┣CMakelists.txt (src)
   ┣main.cpp
   ┣mainwindow.h
   ┣mainwindow.cpp
   ┗mainwindow.ui

my cmake root :

cmake_minimum_required(VERSION 3.10.0 FATAL_ERROR)

project(test_1 LANGUAGES CXX)

set(CMAKE_INCLUDE_CURRENT_DIR ON)

set(Qt_PATH "E:/Qt")
set(Qt_VERSION "5.14.2")
set(Qt_PROJECT "mingw73_32")
set(Qt5_DIR ${Qt_PATH}/${Qt_VERSION}/${Qt_PROJECT}/lib/cmake/Qt5 CACHE STRING "")

find_package(Qt5 REQUIRED COMPONENTS Core Widgets Gui)

set(project_ui 
    src/mainwindow.ui)

set(project_headers 
    src/mainwindow.h)

set(project_sources 
    src/main.cpp
    src/mainwindow.cpp)

qt5_wrap_ui(project_headers_wrapped ${project_ui})
qt5_wrap_cpp(project_sources_moc ${project_headers})

# Block 1
add_executable(${PROJECT_NAME} ${project_headers} ${project_sources} ${project_sources_moc} ${project_headers_wrapped})

# Block 2
add_executable(${PROJECT_NAME} ${project_headers} ${project_sources})
add_subdirectory(src)

target_link_libraries(${PROJECT_NAME}
    PUBLIC 
    Qt5::Core
    Qt5::Gui
    Qt5::Widgets)

set(Qt_DLL "libstdc++-6" "libwinpthread-1" "Qt5Core" "Qt5Widgets" "Qt5Gui")
# dll
foreach(dll ${Qt_DLL})
    file(
        COPY ${Qt_PATH}/${Qt_VERSION}/${Qt_PROJECT}/bin/${dll}.dll
        DESTINATION ${CMAKE_BINARY_DIR}
    )
endforeach()

My cmake src :

set(project_ui 
    mainwindow.ui)

set(project_headers 
    mainwindow.h)

qt5_wrap_ui(project_headers_wrapped ${project_ui})
qt5_wrap_cpp(project_sources_moc ${project_headers})

target_sources(
    ${PROJECT_NAME}
    PRIVATE
    ${project_sources_moc} ${project_headers_wrapped}
)

When I enable the Block 1 the cmake project works ! When the Block 2 is enable (so, with the cmake src) the ui_mainwindow.h and moc_mainwindow.cpp will never generated and I don't know why :/

thank's for a solution. Sorry if the solution is easy to found because I don't understand what is this problem.

Christian Ehrlicher

@BrigitteLPB said in Qt5 and Cmake : strange behavior with wrapp_ui/cpp:

When I enable the Block 1 the cmake project works ! When the Block 2 is enable (so, with the cmake src) the ui_mainwindow.h and moc_mainwindow.cpp will never generated and I don't know why :/

Because the first version is the correct one, the second not. See the documentation: https://doc.qt.io/qt-5.12/qtwidgets-cmake-qt5-wrap-ui.html#examples

When you don't add the output files as dependency to your target then noone knows that those files are needed.

BrigitteLPB

Hi,
Thanks for the answer, but I don't understand what you mean. Have you some code to fix my cmake src ? Is it a wrong utilization of target_sources ?

Christian Ehrlicher

@BrigitteLPB said in Qt5 and Cmake : strange behavior with wrapp_ui/cpp:

Have you some code to fix my cmake src ?

The first version works and is correct.