Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5

QMatthias

Hello Qt community,

I have just updated Visual Studio 2017 (minor Update) from Version 15.7.4 to 15.8.0.
I use Qt 5.9.5 and Windows 10. Now I get some errors in Visual Studio concerning the Qt library.

Error (active)	E2512	the argument to a feature-test macro must be a simple identifier
in qcompilerdetection.h	Line 1350

Error	C3615	constexpr function 'qCountLeadingZeroBits' cannot result in a constant expression (compiling source file main.cpp) in	qtcore\qalgorithms.h line 847

Do I have to adapt one or more settings in Visual Studio 15.8.0 to work with Qt 5.9.5?
Or is there a new Qt 5.9.x Version available for this problem?

Thank you in advance for your help and your support.

Many greetings,
Matthias

kkoehne

Just updated to Visual Studio 2017 15.8.0. Anyhow, i could not reproduce your problem.

cl /version prints

Microsoft (R) C/C++ Optimizing Compiler Version 19.15.26726 for x64

for me. Also, what configure options did you use?

BugCrasher

Hello Kai Köhne,

thank your for your help and fast response.
I'm not in the office - so I use my personal account.
My configuration is definitely x86 / 32-Bit - not x64.
I will give you the complete configuration string by tomorrow.

I apologize for the delay.

Greetings,
Matthias

devDawg

Easiest solution is to just not use Visual Studio. It's an unnecessarily bulky framework that, if I'm not mistaken, runs wayyy slower than Qt.

At the very least, re-consider WHY you want to use Visual Studio. If it's for specific APIs or libraries, there's a good chance they're probably available for Qt, as well. (open source is a wonderful thing)

SGaist

Hi and welcome to devnet,

Please take a look at this thread about VS 15.8 on the development mailing list.

QMatthias

Hello Qt community,

@kkoehne My configuration is:

Microsoft (R) C/C++ Optimizing Compiler Version 19.15.26726 for x86

@devDawg You are absolute right. But this is a company decision - I have to use Visual Studio.

@SGaist thank you very much. In the mailing list is recommended to delte ".qmake.stash" files. I don't find any ".qmake.stash files" on my hard disk. I use Microsoft Visual Studio 2007 only and do not use qmake. I use the Visual Studio Plugin "Qt VS Tools" to generate the Visual Studio Project for Qt.
Today I generated a complete new fresh Project (Qt GUI Application with "Qt VS Tools"), and I have the same errors as with my main project yesterday. So my problem is not solved.

Thanks to all!

Many greetings from Germany,
Matthias

QMatthias

Hello Qt community,

sorry, I have missed an entry in the mailing list.
This is a known with Qt and VS problem.

quote from mailing list:
"Another issue: 5.9 doesn't build in 32-bit x86. Fix is in
https://codereview.qt-project.org/236948 (backport of
c59cb9809559f0aae6be8544cb2049e41f8040e9)."

Thanks to all!

Many greetings from Germany,
Matthias

QMatthias

Hello Qt community,

Success! With the new "qalgorithms.h" the x86 build works great again.
For your information:
[https://codereview.qt-project.org/#/c/236948/2/src/corelib/tools/qalgorithms.h](link url)

Special thanks to @SGaist !

Problem solved!

Many greetings from Germany,
Matthias

sivabudh

I too just upgraded to version 15.8.0 yesterday running Qt 5.10.1 on Windows x86 (32-bit) and ran into the same problem. My solution was to downgrade to 15.7.6.

Doctor G

@QMatthias

I replace the qalgorithms.h cleaned the cmake cache, did a full rebuild. And now it is working for me also.

I am using VS2017 15.9.4 and doing a x64 build with release symbols.

Taytoo

I'm getting this error on 5.12.0 static x86 build in Visual Studio 2017. Is the fix same?

Christian Ehrlicher

@Taytoo said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

Is the fix same?

If you use 15.8 then yes - it makes no different if you build Qt static or not here.

Taytoo

@Christian-Ehrlicher I have Visual Studio 2017 15.9.6 and Qt 5.12.0. Just tried the fix and its Not working.

Christian Ehrlicher

@Taytoo said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

Just tried the fix and its Not working.

Which fix?

Taytoo

@Doctor-G said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

@QMatthias

I replace the qalgorithms.h cleaned the cmake cache, did a full rebuild. And now it is working for me also.

I am using VS2017 15.9.4 and doing a x64 build with release symbols.

@Christian-Ehrlicher said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

@Taytoo said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

Just tried the fix and its Not working.

Which fix?

The one above

Christian Ehrlicher

Then I would say - update to 5.9.7 and make sure no old Qt version is around and try again since it's fixed in 5.9.7

Taytoo

@Christian-Ehrlicher you mean downgrade Qt from 5.12.0 to 5.9.7 - that's quite an old version. I need the high-dpi support in Qt.

Can anyone look into this issue, I'm sure I'm not the only one on 5.12.0 branch using VS2017?

Christian Ehrlicher

You're using 5.12? Then the fix is in there already... the problem here was only due to problems with Qt5.9.5/.6 and VS 2017...
Do you compile Qt on your own?

Taytoo

@Christian-Ehrlicher said in Problem with new Visual Studio update 2017 Version 15.8.0 and Qt 5.9.5:

You're using 5.12? Then the fix is in there already... the problem here was only due to problems with Qt5.9.5/.6 and VS 2017...
Do you compile Qt on your own?

Yes and Yes

Taytoo

Fixed preprocessor error by updating header file:

#if defined(__cplusplus)
#if defined(__clang__)
#if QT_HAS_CPP_ATTRIBUTE(clang::fallthrough)
#    define Q_FALLTHROUGH() [[clang::fallthrough]]
#endif
#elif defined(__GNUC__)
#if QT_HAS_CPP_ATTRIBUTE(gnu::fallthrough)
#    define Q_FALLTHROUGH() [[gnu::fallthrough]]
#endif
#elif QT_HAS_CPP_ATTRIBUTE(fallthrough)
#  define Q_FALLTHROUGH() [[fallthrough]]
#endif
#endif