Including MQTT wrapper for mosquitto library on windows

[starkm42]

@Dean21 i am thinking this is because you forgot to add DEPENDPATH

source: https://doc.qt.io/qt-6/qmake-variable-reference.html#dependpath

Specifies a list of directories for qmake to scan, to resolve dependencies. This variable is used when qmake crawls through the header files that you #include in your source code.

when using 3rd party libraries, this method is much more easy and less error prone. https://doc.qt.io/qtcreator/creator-project-qmake-libraries.html

Qt modifies your qmake file for you.

[jsulm]

@Dean21 I think on Windows you need to link differently (see https://doc.qt.io/qt-6/qmake-variable-reference.html#libs):

unix:LIBS += -L/usr/local/lib -lmath
win32:LIBS += c:/mylibs/math.lib

So, you need to use a path to the *.lib file of the library.

"the kit used when I made this project says it is Desktop Qt 6.4.1 MinGW 64-bit for the compiler" - the question is - what compiler was used to build that library? If MSVC was used it is not going to work. You need a MinGW build of the lib.

[Dean21]

@starkm42 Thanks for the reply, that seemed to work to remove a lot of the linking errors but not I get this one error I havent seen before

:-1: error: No rule to make target 'C:/Users/deanm/Desktop/Uni_Year_3/3rd_year_project/Microscope_GUI_V2/Microscope_GUI/../../../../../../../Program Files/mosquitto/devel/libmosquittoppd.a', needed by 'debug/Microscope_GUI.exe'. Stop.

[jsulm]

@Dean21 How does your pro file look like now?

[Dean21]

@jsulm I am not sure what compiler was used to compile the library, but as I have had this working in Qt creator before on linux with the same library I assumed it would work fine on windows

[Dean21]

@jsulm This is now my .pro file.

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

#QMAKE_CXXFLAGS += -lmosquitto

#INCLUDEPATH += "C:/Program Files/mosquitto/devel"

#LIBS += -L"C:/Program Files/mosquitto/devel" -lmosquittopp

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    QMMqttClient.cpp \
    main.cpp \
    widget.cpp \

HEADERS += \
    QMMqttClient.h \
    widget.h

FORMS += \
    widget.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittopp
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittoppd
else:unix: LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittopp

INCLUDEPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'
DEPENDPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'

win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittopp.a'
else:win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittoppd.a'
else:win32:!win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/mosquittopp.lib'
else:win32:!win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/mosquittoppd.lib'
else:unix: PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittopp.a'

[jsulm]

@Dean21 said in Including MQTT wrapper for mosquitto library on windows:

else:unix: PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittopp.a'

Why do you have this?
Your LIBS for Windows are still wrong.

[Dean21]

@jsulm Sorry forgot to untick linux and mac boxes, here is the .pro file, it still has the same error though.

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

QMAKE_CXXFLAGS += -lmosquitto

INCLUDEPATH += "C:/Program Files/mosquitto/devel"

LIBS += -L"C:/Program Files/mosquitto/devel" -lmosquittopp

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    QMMqttClient.cpp \
    main.cpp \
    widget.cpp \

HEADERS += \
    QMMqttClient.h \
    widget.h

FORMS += \
    widget.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittopp
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittoppd

INCLUDEPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'
DEPENDPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'

win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittopp.a'
else:win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittoppd.a'
else:win32:!win32-g++:CONFIG(release, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/mosquittopp.lib'
else:win32:!win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/mosquittoppd.lib'

Error: :-1: error: No rule to make target 'C:/Users/deanm/Desktop/Uni_Year_3/3rd_year_project/Microscope_GUI_V2/Microscope_GUI/../../../../../../../Program Files/mosquitto/devel/libmosquittoppd.a', needed by 'debug/Microscope_GUI.exe'. Stop.

[jsulm]

@Dean21 said in Including MQTT wrapper for mosquitto library on windows:

QMAKE_CXXFLAGS += -lmosquitto

Why?

And again: your LIBS for Windows are wrong!

I also don't know why you have static versions if you want to link dynamically:

else:win32-g++:CONFIG(debug, debug|release): PRE_TARGETDEPS += $$PWD/'../../../../../../../Program Files/mosquitto/devel/libmosquittoppd.a'

Remove alls these *.a stuff.

[Dean21]

@jsulm My bad, this was done with dynamic and this is what was generated in the .pro file now.

QT       += core gui

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

QMAKE_CXXFLAGS += -lmosquitto

INCLUDEPATH += "C:/Program Files/mosquitto/devel"

LIBS += -L"C:/Program Files/mosquitto/devel" -lmosquittopp

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    QMMqttClient.cpp \
    main.cpp \
    widget.cpp \

HEADERS += \
    QMMqttClient.h \
    widget.h

FORMS += \
    widget.ui

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittopp
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/'../../../../../../../Program Files/mosquitto/devel/' -lmosquittoppd

INCLUDEPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'
DEPENDPATH += $$PWD/'../../../../../../../Program Files/mosquitto/devel'

This now gives these errors:

:-1: error: cannot find -lmosquittoppd
:-1: error: cannot find -lmosquittod
:-1: error: collect2.exe: error: ld returned 1 exit status

[starkm42]

@Dean21 wait are you using the same compiled library that you used for linux on windows without recompiling or getting new binaries compiled for windows ?

@Dean21 said in Including MQTT wrapper for mosquitto library on windows:

@jsulm I am not sure what compiler was used to compile the library, but as I have had this working in Qt creator before on linux with the same library I assumed it would work fine on windows

[Dean21]

@starkm42 No, i just redownloaded the library from the website and set it up to start with to make sure it was working before i tried to use it in qt

[Dean21]

I just re-added the library, but removed the tickbox for "add d suffix for debug", and that removes the errors about finding -mosquitoppd, but now I have all the same linker errors again.

[starkm42]

@Dean21

for adding a test library called NemaTode, after following the guide https://doc.qt.io/qtcreator/creator-project-qmake-libraries.html

this is what my qmake looks like

QT       += core gui positioning

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    gpssource.cpp \
    main.cpp \
    mainwindow.cpp

HEADERS += \
    gpssource.h \
    mainwindow.h

# Default rules for deployment.
qnx: target.path = /tmp/$${TARGET}/bin
else: unix:!android: target.path = /opt/$${TARGET}/bin
!isEmpty(target.path): INSTALLS += target

win32:CONFIG(release, debug|release): LIBS += -L$$PWD/../../third_party_libs/NemaTode/lib/ -lNemaTode
else:win32:CONFIG(debug, debug|release): LIBS += -L$$PWD/../../third_party_libs/NemaTode/lib/ -lNemaTode
else:unix: LIBS += -L$$PWD/../../third_party_libs/NemaTode/lib/ -lNemaTode

INCLUDEPATH += $$PWD/../../third_party_libs/NemaTode/include/nmeaparse
DEPENDPATH += $$PWD/../../third_party_libs/NemaTode/include/nmeaparse

FORMS += \
    GPSCordinatesDisplay.ui

mine does not have LIB or INCLUDEPATH
try removing all manual additions, just sticking to the guide would be my suggestion.

[Dean21]

@starkm42 Thanks for the reply, the issue was to do with the fact mosquitto was compiled with a different library. To avoid this I am just going to run a ubuntu VM Thanks everyone for the help.