Build Qt entirely with -no-c++11 for iOS

[eliot]

Hi.

I have to build Qt 5.5.0 with -no-c++11 configure option for iOS.

I tried but failed.

Is this possible?

[SGaist]

Hi and welcome to devnet,

What error did you get ? What sources did you use ?

[eliot]

@SGaist

Thank you for your reply.
I tried to build again using 5.5.1 source from Qt installer but failed.
First, this is the configure options I'm using.

-xplatform macx-ios-clang \
-sdk iphoneos8.4 \
-opensource \
-release \
-prefix /opt/qt/5.5.1/ios \
-confirm-license \
-nomake examples \
-nomake tests \
-no-c++11

and this error is occurred.

/Users/eliot/Library/Qt5.5.1/5.5/Src/qtbase/src/plugins/platforms/ios/qiosviewcontroller.mm:258:107: error: expected identifier
m_focusWindowChangeConnection = QObject::connect(qApp, &QGuiApplication::focusWindowChanged, [self]{
^
1 error generated.

So I modified qiosviewcontroller.mm and commented out line 230, 248~260 that like this.

http://i.imgur.com/co24FhU.png

and the error is gone but another error is happened.

/Users/eliot/Library/Qt5.5.1/5.5/Src/qtbase/src/plugins/platforms/ios/qiosfileengineassetslibrary.mm:130:10: error: no type named 'atomic_bool' in namespace 'std'
std::atomic_bool m_stop;
~~~~~^
/Users/eliot/Library/Qt5.5.1/5.5/Src/qtbase/src/plugins/platforms/ios/qiosfileengineassetslibrary.mm:130:22: warning: private field 'm_stop' is not used [-Wunused-private-field]
std::atomic_bool m_stop;
^

Can I replace atomic_bool to primitive bool in here?

As I know, atomic is included since C++11.
So I think Qtbase's iOS plugin is based on C++11.
Therefore I think I can't build Qt with -no-c++11 option.
That's why I asked "Is this possible?".

[SGaist]

Indeed those are C++11 features. But before doing changes to avoid use of C++11: why do you want to disable C++11 in Qt's build ?

[eliot]

@SGaist

I'm working with a DRM/CAS company now.

Their DRM/CAS libraries and build tools support only libstdc++.

and their build tools replace Xcode's clang, ld and something as a wrapper.

So when I compile our source (Qt iOS) with these things in Xcode, a few link errors are occurred.

Because of that, I have to disable C++11.

[SGaist]

Are they aware that we're almost in 2016 ?

No, since m_stop is a flag, you can replace it with a QAtomicInt, the handling is a bit different but at least you're still using an atomic operation to do it.

Then replace the lambda by a private slot.

You can't just comment out code like that and expect it to continue to work the same.

[eliot]

@SGaist

well.. I don't understand them, too. They are very famous company in the fields but very old fashioned.

anyway I'll try to fix that. Thank you for your advices.