How to build .so files from existing C++ app using Qt Creator

JacobNovitsky

I know how to create Shared Library using New Project / .. notation
but how to make the same using existing project, it must be some flags/commands in Projects/Build/Run settings
Please share the instructions

jsulm

@JacobNovitsky Do you mean you want to change a project which builds to an executable so that a shared library is created instead?
You need to change pro or CMakeLists.txt file of that project. You can simply compare it with a project which generates a shared library.

JacobNovitsky

In my shared library pro file there are following lines:

CONFIG -= qt

TEMPLATE = lib
DEFINES += SHARED_LIBRARY

CONFIG += c++17

# You can make your code fail to compile if it uses deprecated APIs.
# In order to do so, uncomment the following line.
#DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0x060000    # disables all the APIs deprecated before Qt 6.0.0

SOURCES += \
    Shared.cpp

HEADERS += \
    shared_global.h \
    Shared.h

# Default rules for deployment.
unix {
    target.path = /usr/lib
}
!isEmpty(target.path): INSTALLS += target

What should I do in .pro file of project I want to build to .so files?
I can suppose that I need to create global shared_global.h analog for each class (header) I have?

if so, should I make it manually or you have tool to make it automatically

SGaist

@JacobNovitsky you are already using the lib template so it should build a library. You don't need one xxxx_globals.h per classe. It's a header that exists once per module.

JacobNovitsky

@SGaist yes, understood
but what should I do to make shared lib from existing project?

SGaist

@JacobNovitsky the project you are showing here already creates a library. That is the result you will get when compiling it.

So what exactly is your issue ?

JacobNovitsky

@SGaist
I'm trying to make .so file using this pro file for new C++ project

TEMPLATE = lib
CONFIG += c++17
CONFIG -= app_bundle
CONFIG -= qt

SOURCES +=
TestClass.cpp

HEADERS +=
TestClass.h

Set the target type to shared

CONFIG += shared

Set the output directory for the shared library

DESTDIR = /home/j/
TARGET = $$DESTDIR/libTestLib.so

it builds, but there is no .so file

upd: this pro file version made these dirs and its contains
j@j-BOHB-WAX9:~/testNewLib-Debug/shared-LIB/shared-LIB$ ls
liblibTestLib.so.so liblibTestLib.so.so.1.0
liblibTestLib.so.so.1 liblibTestLib.so.so.1.0.0

TEMPLATE = lib
CONFIG += c++17
CONFIG -= app_bundle
CONFIG -= qt

SOURCES += \
    TestClass.cpp

HEADERS += \
    TestClass.h

# Set the target type to shared
CONFIG += shared

# Set the output directory for the shared library
DESTDIR = shared-LIB
TARGET = $$DESTDIR/libTestLib.so

SGaist

@JacobNovitsky TARGET should just contain the name of the library. Nothing else. No prefix, no suffix.