undefined reference to `vtable for shutdown'

[JoeCFD]

@SPlatten this is wrong. You have always to have virtual in front of a destructor. Otherwise, you may have unpleasant memory leak in your apps.

[JonB]

@SPlatten
I am lost at this point. It might be that one of the experts knows better than I what situation you are in. You would have to wait for them to see this, perhaps later.

At this point, if I were you and I had nothing else to do I would probably take what you have and put it into a brand new, from scratch, standalone tiny project (maybe get rid of the .ui file too) and see if I could get it working as (a) a standalone Qt program (provide a main()) and (b) whatever you are doing for " I have added a class [to] one of the libraries" which I don't know about.

public:
    shutdown(const char* cpszText, QWidget *pParent = 0);
    ~shutdown();

I do think you should write virtual ~shutdown(); here, just in case.

[SPlatten]

@JoeCFD , ok, I've changed the constructor so it is prefixed with explicit and the destructor with virtual which goes back to how it was and I still have the same issue.

[SPlatten]

@JonB , I believe this issue is because the build process is using just cmake and hasn't been done with Qt Creator. I can't change it, its an old system that is evolving over time.

[SPlatten]

Just for completeness, here is the actual content of the CMakeLists.txt file:

cmake_minimum_required(VERSION 2.8.10)
include (flexelint) 

set (CMAKE_AUTOUIC ON)
set (CMAKE_AUTOMOC ON)
set (CMAKE_AUTORCC ON)
set (CMAKE_INCLUDE_CURRENT_DIR ON)

set (FORMS shutdown_ui)
set (HEADERS shutdown.h
             ui_shutdown.h)
set (sources shutdown.cc)
set (output vip_backend)
add_library(${output} STATIC ${sources})
find_package(Qt4 REQUIRED)
include(${QT_USE_FILE})
foreach(loop_var ${QT_LIBRARIES})
  string(REPLACE lib64 lib32 loop_var ${loop_var})
  set(QT_LIBRARIES_32 ${QT_LIBRARIES_32} ${loop_var})
endforeach(loop_var)
qt4_wrap_ui(UI_HEADERS ${FORMS})
qt4_wrap_cpp(MOC_SRCS ${HEADERS})
target_link_libraries(${output} ${QT_LIBRARIES_32})
add_flint(${output})

I have no idea what flexelint is or what it does, same is true of add_flint(${output}).

[JoeCFD]

@SPlatten forget about Qt Creator. Try to build it from command line
Delete build folder
Create build folder
From build folder cmake ${myvariable}
From build folder make VERBOSE=1
add verbose to see more build details.

[SPlatten]

@JoeCFD , that is exactly all I am doing. Also cmake is version 2.8.10.2

rm -R build
mkdir build
cd build
cmake ${myvariable}
make 

In the CMakeLists.txt file I have:

set (CMAKE_VERBOSE_MAKEFILE ON)

[JoeCFD]

@SPlatten Jesus, your cmake is old.

[SPlatten]

@JoeCFD , its very frustrating, its very unusual to find a company these days that are so behind on revisions.

[JoeCFD]

@SPlatten
rm -R build
mkdir build
cd build
cmake ${myvariable}
make VERBOSE=1

[SPlatten]

@JoeCFD , doing that now.

[JoeCFD]

@SPlatten As Jon commented, you can comment the destructor code out and build. It is a small leak. Not a big deal. shutdown is not a good name for class. Try to avoid to use any system command names as your class names. Name it for example ShutdownWindow.

[SPlatten]

@JoeCFD , will try this now.

[SPlatten]

@JoeCFD , output has changed:

../../(usage.cc.o): In function 'shutdownNotice(char cont*)':
vip_system.cc:(.text+0xe1): undefined reference to `vtable for shutdown'
vip_system.cc:(.text+0xe9): undefined reference to `vtable for shutdown'
vip_system.cc:(.text+0x100): undefined reference to `vtable for shutdown'
vip_system.cc:(.text+0x108): undefined reference to `vtable for shutdown'
../../(shutdown.cc.o): In function 'shutdown::shutdown(char cont*, QWidget*)':
shutdown.cc:(text+0x3a): undefined reference to `vtable for shutdown'
../../(shutdown.cc.o):shutdown.cc(.text+0x41): more undefined references to `vtable for shutdown' follow collect2 ld returned 1 exit status

[JoeCFD]

are you building on Linux, right? If yes, change your class name with ShutdownWindow (do not forget the ui file).

[SPlatten]

@JoeCFD , yes Linux...will give it a go (renaming I mean).

[SPlatten]

@JoeCFD, I've changed the class names, do the filenames also need to be changed?

[JoeCFD]

@SPlatten better. But not necessary. Try to build to see if it works.

[SPlatten]

@JoeCFD , I was hoping this was going to solve the problems, but sadly not, the reports messages are the same just "shutdownWindow" now instead of "shutdown".

[JoeCFD]

@SPlatten something weird is going here. This means you can not add any class to your project. You must have other classes. Copy it and change its name to ShutdownWindow. Add it to your project. May I see your
make VERBOSE=1 output?