How to differentiate between VS2017/2019 and older Visual Studio versions in qmake .pro file?

Bart_Vandewoestyne

According to https://docs.microsoft.com/en-us/cpp/build/reference/permissive-standards-conformance?view=msvc-160 the /permissive- flag is only supported since VS2017. I wanted to use that compiler flag for my project, but only if it is compiled with VS2017 or later. I am using Qt 5.15.1. I tried using

    win32-msvc2017 | win32-msvc2019 {
        QMAKE_CXXFLAGS += /permissive-
    }

but that fails, because there are no win32-msvc2017 nor win32-msvc2019 in the mkspecs directory of my Qt 5.15.1 install. There is only a win32-msvc directory. How can I specify that the /permissive- flag should only be used when compiling my project with VS2017 or later?

Christian Ehrlicher

You can try the (undocumented) variable QMAKE_MSC_VER (see mkspecs\common\msvc-version.conf)

Bart_Vandewoestyne

@Christian-Ehrlicher said in How to differentiate between VS2017/2019 and older Visual Studio versions in qmake .pro file?:

You can try the (undocumented) variable QMAKE_MSC_VER (see mkspecs\common\msvc-version.conf)

To specify that I only want to use the /permissive- flag from VS2017 on and later, I just tried

    greaterThan(QMAKE_MSC_VER, 1900) {
        QMAKE_CXXFLAGS += /permissive-
    }

which is similar to the code in mkspecs\common\msvc-version.confand that seems to work:

DEBUG 2: evaluating joined expression
DEBUG 2: new string
DEBUG 2: literal "QMAKE_MSC_VER"
DEBUG 2: evaluated expression => QMAKE_MSC_VER
DEBUG 2: evaluating joined expression
DEBUG 2: new string
DEBUG 2: literal "1900"
DEBUG 2: evaluated expression => QMAKE_MSC_VER 1900
DEBUG 1: D:/blablabla.pri:83: calling built-in greaterThan(QMAKE_MSC_VER, 1900)
DEBUG 1: D:/blablabla.pri.pri:83: test function returned true
DEBUG 1: D:/blablabla.pri.pri:83: taking 'then' branch
DEBUG 1: D:/blablabla.pri.pri:83: entering block

Thanks!