Building 5.2 (stable) with libc++ for c++11 support?

[rosetter]

Hi all,

It seems that the iOS configuration builds Qt against the libstdc++ GNU library and not the default, libc++. The libstdc++ included in the iOS SDK appears to be old and lacking c++11 support.

Has anyone built Qt for iOS with c++11 support? In theory the compiler/linker flag "-stdlib=libc++" should fix everything, but I don't know where that's being set...

Any advice?

Thanks,
Tyler

[SGaist]

Hi,

It should be set in the macx-ios-clang mkspec

[rosetter]

Thanks SGaist. I seem to have gotten it working by adding "c++11" to the "CONFIG +=" line in qtbase/mkspecs/macx-ios-clang/qmake.conf.

This should be the default, as libc++ is now the default for iOS and the provided libstdc++ is old and doesn't include c++11 support. Should this be a bug report?

[SGaist]

Before that you should ask on the interest mailing list, you'll find Qt's developers/maintainers there (this forum is more user oriented). Don't forget to subscribe first.

[kersson]

So was the solution to recompile Qt for iOS with c++11 using the method that rosetter described (modifying the qtbase/mkspecs/macx-ios-clang/qmake.conf file)?

[rosetter]

[quote author="kersson" date="1392188702"]So was the solution to recompile Qt for iOS with c++11 using the method that rosetter described (modifying the qtbase/mkspecs/macx-ios-clang/qmake.conf file)?[/quote]

yes, that's what works for me.

[kortus]

Hi rosetter,

I have changed the qmake.conf in the way you described. But after a configure the line which shows the C++11 support says no.

"see":http://qt-project.org/forums/viewthread/38373/#162619

Will it work yet?

[kersson]

kortus, even though the line says C++11...no, it is actually enabled. I confirmed that after making the change to the mkspec and compiling Qt for iOS, I was able to compile and deploy projects with CONFIG += c++11 for both simulator and device.

However, I'm still working on a solving a "semi-related issue.":http://qt-project.org/forums/viewthread/38541/

Let me know if you have any thoughts :)

[kortus]

kersson, you are right, it works.

[fpelliccioni]

Hi rosetter,

Could you please provide us the steps for doing the Qt compilation?

Thanks

[fpelliccioni]

Hi SGaist,

Is there any information about the compilation steps of the Qt provided at http://qt-project.org/downloads?

Thanks

[SGaist]

Hi,

Do you mean the exact parameter they use ?

Personally I used the line provided "here":http://qt-project.org/doc/qt-5/building-from-source-ios.html

[fpelliccioni]

SGaist, thanks for replying.

Yes, I meant that (Sorry for my english).
What if I want to build all the Qt "products" included in the download page?
I want to build them in the same way (exact the same) as Qt does.

My question is: what are the parameters (to the configure script) used by Qt for the products provided in the download page?
Is there any information about this?

I have another doubt:

I checked the file:
5.3/ios/mkspecs/macx-ios-clang/qmake.conf

that includes:
5.3/ios/mkspecs/common/clang-mac.conf

In the last file, the following is specified:
QMAKE_CXXFLAGS_CXX11 += -stdlib=libc++
QMAKE_LFLAGS_CXX11 += -stdlib=libc++

(This is the same for Qt5.2)

According to what I understand, Qt 5.2 and 5.3 (ios) are compiled to use LibC++.
I do not understand why it is not.

Thanks!
Fernando.

[SGaist]

You have that "wiki entry":http://qt-project.org/wiki/Building-Qt-Package that explains how.

I don't understand your last question. Since 5.2, they do use libc++