Qt + firebase C++ SDK linking issues on iOS

kuzulis

Hi all,

I have following build env:

host: OSX 10.12 Sierra
XCode 9.2
Qt 5.10.1 for iOS
QtCreator 4.7.0
firebase 5.2

and try to build my application from QtCreator for iOS with the firebase support, but it fails with following linking errors:

Undefined symbols for architecture arm64:
  "_OBJC_CLASS_$_FIRMessaging", referenced from:
      objc-class-ref in firebase_messaging(messaging_231c52c311096cfce13e67fa91eb9ac5.o)
  "_OBJC_CLASS_$_FIRApp", referenced from:
      objc-class-ref in firebase(app_ios_814e1620d4f88024cea4bade26623a67.o)
  "_OBJC_CLASS_$_FIROptions", referenced from:
      objc-class-ref in firebase(app_ios_814e1620d4f88024cea4bade26623a67.o)
ld: symbol(s) not found for architecture arm64
clang: error: linker command failed with exit code 1 (use -v to see invocation)

I have simplified my project to following code:

== main.cpp ==

#include <QCoreApplication>

#include <firebase/app.h>
#include <firebase/messaging.h>
#include <firebase/util.h>

int main(int argc, char *argv[])
{
    QCoreApplication a(argc, argv);
    ::firebase::App *fapp = ::firebase::App::Create();
    Q_UNUSED(fapp);
    return a.exec();
}

and a project file is:

QT -= gui
CONFIG += c++11 console
CONFIG -= app_bundle

# Check for GOOGLE_FIREBASE_SDK environment variable.
ENV_GOOGLE_FIREBASE_SDK = $$(GOOGLE_FIREBASE_SDK)
# Or define GOOGLE_FIREBASE_SDK path here.
GOOGLE_FIREBASE_SDK =

isEmpty(ENV_GOOGLE_FIREBASE_SDK) {
    isEmpty(GOOGLE_FIREBASE_SDK) {
        message("GOOGLE_FIREBASE_SDK" environment variable not detected!)
    }
}

INCLUDEPATH += $$(GOOGLE_FIREBASE_SDK)
INCLUDEPATH += $$(GOOGLE_FIREBASE_SDK)/include

SOURCES += \
        main.cpp

FCM_LIBS_PATH = $$(GOOGLE_FIREBASE_SDK)/frameworks/ios/universal
message("FCM_LIBS_PATH = $$FCM_LIBS_PATH")

LIBS += -F$$FCM_LIBS_PATH \
   -framework firebase_messaging \
   -framework firebase \
   -framework Foundation \
   -framework UserNotifications \
   -framework UIKit \
   -framework CoreGraphics

The firebase SDK contains different frameworks directories for different architectures :

~/firebase_cpp_sdk/frameworks/ios/universal
~/firebase_cpp_sdk/frameworks/ios/amd64
~/firebase_cpp_sdk/frameworks/ios/i386
~/firebase_cpp_sdk/frameworks/ios/x86_64
~/firebase_cpp_sdk/frameworks/ios/armv7

As I see that error related to 'arm64' architecture, so, I have changed the project file LIBS to use 'arm64' instead of 'universal', but this does not help.

Also I tried to build the project from the XCode, using qmake's generated xcode.project file, but there are same error.

I looked on stackoverflow similar issues, but that workarounds does not help:

I tried to remove the /Users/admin/Library/Developer/Xcode/DerivedData directory.
I tried to play with the XCode options "Build Settings -> Build Active Architecture Only -> <yes/no>"

I looked a code from the following projects:

qtcloudmessaging: https://github.com/qt/qtcloudmessaging
QtFirebase: https://github.com/Larpon/QtFirebase

But I don't understand why this linker error happens.. Maybe is it a qmake bug?

pets

I cannot help you with the problem but here Firebase works without problems. Have you tried to run qmake again, or delete the generated files?

kuzulis

but here Firebase works without problems

Where is "here" ?

Nominate our 2022 Qt Champions!

Qt + firebase C++ SDK linking issues on iOS