Exclude qmath.h from build

[gmk27]

Hi, I have an app (compiled on msvc201x) which uses math.h from VS include path. While building, qmath.h is being auto-included and leading to lot of macro redefs. I did try some procedures on internet but didn't work for me.

Any help is appreciated...

[Christian Ehrlicher]

I can include math.h and qmath.h without getting any compiler warnings or errors here.
What Qt-version and MSVC compiler do you use?

This is working fine:

#include <math.h>
#include <qmath.h>

int main(int argc, char** argv)
{
	return 0;
}

The order of the both includes also don't matter.

[gmk27]

@Christian-Ehrlicher MSVC2013. Qt creator 4.14.2 Qt 5.15.2
the solution you suggested is tried already. That didn't work for me somehow.
Let me try once again and confirm.

[Christian Ehrlicher]

Qt5.15 can not be use with this ancient compiler: https://doc.qt.io/qt-5/supported-platforms.html

[gmk27]

oh okay that explains the problem I guess. I tried again. It didn't work. VS2019 is what you suggest right?

[gmk27]

@Christian-Ehrlicher said in Exclude qmath.h from build:

Qt5.15 can not be use with this ancient compiler: https://doc.qt.io/qt-5/supported-platforms.html

I have installed VS2019 now. With MSVC2013 I don't have errors. Now I have lot of errors with my previous warnings intact. It is between qmath.h and corecrt_math_defines.h. What could be the problem?

[J.Hilk]

@gmk27 can you post the actual wording of the errors?

The new one and the original one, I had a math.h related problem recently and I'm wondering if it could be similar

[Christian Ehrlicher]

@gmk27 said in Exclude qmath.h from build:

What could be the problem?

You're still using the old compiler I would guess.

[gmk27]

@Christian-Ehrlicher No buddy. I have uninstalled VS2013 before installing the 2019 version. It is not even in the KITS, I checked everything.

[gmk27]

@J-Hilk

C4005: M_E: Macro redefinition     -      corecrt_math_defines.h
see previous definition of M_E        -      qmath.h

And so on with all M_* defines. I have included math.h before qmath.h as suggested.

[Christian Ehrlicher]

Please also make sure that not an old WinSDK is installed and used.
The corecrt_math_defines.h must contain something like this:

#ifndef _MATH_DEFINES_DEFINED
    #define _MATH_DEFINES_DEFINED
    // Definitions of useful mathematical constants
    //
    // Define _USE_MATH_DEFINES before including <math.h> to expose these macro
    // definitions for common math constants.  These are placed under an #ifdef
    // since these commonly-defined names are not part of the C or C++ standards

qmath.h properly defines _USE_MATH_DEFINES (line 50)

[gmk27]

@Christian-Ehrlicher - Yes, I see there are proper guard checks in corecrt_math_defines.h. BTW I have Windows 10 SDK installed. I believe it is the latest one. I tried to reproduce the warnings by creating a new Qt project (as in your 1st reply to this post) but these warnings are not popped up, interestingly. Point to note is - these warnings are coming even if I don't include the <qmath.h> in my existing project. I have checked whole project it is nowhere included. In the new project it is just fine (with either files included or only one).

Where should I look exactly to fix this kind of issue?

Just to remind my platform - Qt 5.15 and MSVC2019 kit

[VRonin]

The only conflict I've ever seen in this real is related to min/max functions but it can be easily solved adding NOMINMAX to the preprocessor definitions.