Question

Is there any way to get the version and vendor of the compiler used by the user through qmake? What I need is to disable building some targets of my project when g++ 3.x is used and enable them when g++ 4.x is used.

Update: Most answers targeted the preprocessor. This is something that I want to avoid. I don't want a target to be build for a specific compiler version and I want this decision to be made by the build system.

Was it helpful?

Solution

In addition to ashcatch's answer, qmake allows you to query the command line and get the response back as a variable. So you could to something like this:

linux-g++ {
    system( g++ --version | grep -e "\<4.[0-9]" ) {
        message( "g++ version 4.x found" )
        CONFIG += g++4
    }
    else system( g++ --version | grep -e "\<3.[0-9]" ) {
        message( "g++ version 3.x found" )
        CONFIG += g++3
    }
    else {
        error( "Unknown system/compiler configuration" )
    }
}

Then later, when you want to use it to specify targets, you can use the config scoping rules:

SOURCES += blah blah2 blah3
g++4: SOURCES += blah4 blah5

OTHER TIPS

My answer based on Caleb Huitt - cjhuitt's. But his approach does not work for me.

*-g++ {
    GCC_VERSION = $$system("g++ -dumpversion")
    contains(GCC_VERSION, 6.[0-9]) {
        message( "g++ version 6.x found" )
        CONFIG += g++6
    } else {
        contains(GCC_VERSION, 5.[0-9]) {
            message( "g++ version 5.x found" )
            CONFIG += g++5
        } else {
            contains(GCC_VERSION, 4.[0-9]) {
                message( "g++ version 4.x found" )
                CONFIG += g++4
            } else {
                message( "Unknown GCC configuration" )
            }
        }
    }
}

As you see you can get version from GCC and then compare it with regex expression.

The way how to use is the same:

SOURCES += blah blah2 blah3
g++4: SOURCES += blah4 blah5

As a start, I would look at the scoping feature that qmake supports:

Scopes and Conditions

But while I read about it, it seems that by default you can use general platform conditions like win32 or unix or you can use the name of the qmake spec like linux-g++. You could test the Visual Studio version like this (since the different Visual Studio versions use different qmake specs), but I don't think that you can test the gcc version like this (at least I don't know how).

I do

isEmpty(MGWVER) {
    MGW_MAJ = $$system(echo | gcc -dM -E - | fgrep __GNUC__ | cut -d\" \" -f 3)
    MGW_MIN = $$system(echo | gcc -dM -E - | fgrep __GNUC_MINOR__ | cut -d\" \" -f 3)
    MGWVER =$$MGW_MAJ$$MGW_MIN
    message(MGWVER $$MGWVER)
}

It returns "48". I use it for linking proper boost libraries:

USER_BOOST_CFG=mgw$${MGWVER}-mt-s-$$(BOOST_VER)
message($$USER_BOOST_CFG)
LIBS *= -L$$(BOOST_ROOT)/lib
LIBS *= -L$$(BOOST_ROOT)/stage/lib

LIBS *= -lboost_system-$$USER_BOOST_CFG
LIBS *= -lboost_filesystem-$$USER_BOOST_CFG
LIBS *= -lboost_date_time-$$USER_BOOST_CFG

effectively giving: -lboost_system-mgw48-mt-s-1_54

I am on mingw.

Another idea is to look at QMAKESPEC vaariable and parse from it, hint:

message(QMAKESPEC $$QMAKESPEC)
SPLITED=$$section(QMAKESPEC, "/", 0, -3)
message(SPLITED $$SPLITED)

My answer is based on dismine's answer
We can simply extract the major version number using $$str_member

gcc | clang {
    COMPILER_VERSION = $$system($$QMAKE_CXX " -dumpversion")
    COMPILER_MAJOR_VERSION = $$str_member($$COMPILER_VERSION)
    greaterThan(COMPILER_MAJOR_VERSION, 3): message("gcc 4 or later")
    greaterThan(COMPILER_MAJOR_VERSION, 4): message("gcc 5 or later")
    greaterThan(COMPILER_MAJOR_VERSION, 5): message("gcc 6 or later")
    greaterThan(COMPILER_MAJOR_VERSION, 6): message("gcc 7 or later")
}

Each compiler vendor use to define some specific symbols that identify the compiler and version. You could make the check using those symbols.

I know, for example, that _MSC_VER gives the version of Microsoft C++ Compiler.

What I also know is that Boost Libraries use this kind of feature selection and adaptation.

You can take a look to Boost Config headers, found in include folder, at path: boost/config/* , specially at select_compiler_config.hpp.

By using those compiler specific symbols, you can make feature selection at preprocessing phase of building the code.

The following macros are defined in my version of gcc and g++

#define __GNUC__ 4 
#define __GNUC_MINOR__ 0
#define __GNUC_PATCHLEVEL__ 1

Additionaly the g++ defines:

#define __GNUG__ 4
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