Building a c shared library in QtCreator

Martyn

Hi all,

I have a project that needs to build a DSO with few dependencies and an initialisation function. I'm using QtCreator and qmake.

In the .pro file created I have

TEMPLATE = lib

There is only a single c source file.

It builds the DSO using the c++ compiler . The question is how do I instruct it to use c to link the DSO, and secondly how do I pass additional arguments. I was trying

LINK = cc
LFLAGS += -Wl,-init,MyInit

But neither seem to have an effect....

jsulm

@martyn What is the file name extension of you C file? Is it .cpp or .c?

Martyn

Its ".c" ...

Martyn

Gerd

@martyn
shouldn't that be

QMAKE_LINK = cc
QMKAE_LFLAGS+= -Wl,-init,MyInit

?

aha_1980

@gerd is correct. The question to @Martyn is rather, why is QMAKE_LINK needed?

The question is how do I instruct it to use c to link the DSO

There is no such thing as a C or C++ linker. The linker links just symbols. If your file is compiled with a C++ compiler, then something wents wrong.

Please post the whole .pro file and the complete compile log for reference.

Martyn

@gerd said in Building a c shared library in QtCreator:

@martyn
shouldn't that be
QMAKE_LINK = cc
QMKAE_LFLAGS+= -Wl,-init,MyInit

OK - Yes the QMAKE_ versions do work :-)

@aha_1980 said in Building a c shared library in QtCreator:

@gerd is correct. The question to @Martyn is rather, why is QMAKE_LINK needed?

The question is how do I instruct it to use c to link the DSO

There is no such thing as a C or C++ linker. The linker links just symbols. If your file is compiled with a C++ compiler, then something wents wrong.

Yes - I am wanting to use gcc as the (frontend/driver for the) linker to avoid libstdc++ being linked. To confirm, the source file was always being compiled by the c compiler.

Please post the whole .pro file and the complete compile log for reference.

QT       -= core gui
TARGET = myproject
TEMPLATE = lib
DEFINES += MYPROJECT_LIBRARY
DEFINES += QT_DEPRECATED_WARNINGS
QMAKE_LFLAGS += -Wl,-init,myprojectInit
#QMAKE_LINK = cc

SOURCES += \
        binding.c

HEADERS += \
        binding.h \
        pebinder_global.h 

unix {
    target.path = /usr/lib
    INSTALLS += target
}

This provides the link step as

g++ -Wl,-init,myprojectInit -Wl,-O1 -Wl,-z,relro -shared -Wl,-soname,libmyproject.so.1 -o libmyproject.so.1.0.0 binding.o -lpthread

So, as you say, the question is should qmake be smart enough to realise that c++ isn't needed to link if all the source files are .c.

Though I'm happy to now have a simple solution :-)