Guidelines and HOWTOs/Debugging/Debugging symbols

Debugging symbols allow you to debug your application better. Debugging symbols are added to your binary by the compiler. You have to decide during the cmake step if you want debugging symbols or not. To compile your application with debugging symbols, use

cmake . -DCMAKE_BUILD_TYPE=debugfull

to compile it without debugging symbols, use

cmake . -DCMAKE_BUILD_TYPE=release

Depending on your decision, output generated with the command kDebug will also be (debugfull) or not be (release) added to your application.

As an example, let's start with a hello world application.

main.cpp

#include <KApplication>
#include <KAboutData>
#include <KCmdLineArgs>
#include <KMessageBox>

int main (int argc, char *argv[])
{
    KAboutData aboutData(
                         // The program name used internally.
                         "tutorial1",
                         // The message catalog name
                         // If null, program name is used instead.
                         0,
                         // A displayable program name string.
                         ki18n("Tutorial 1"),
                         // The program version string.
                         "1.0",
                         // Short description of what the app does.
                         ki18n("Displays a KMessageBox popup"),
                         // The license this code is released under
                         KAboutData::License_GPL,
                         // Copyright Statement
                         ki18n("(c) 2007"),
                         // Optional text shown in the About box.
                         // Can contain any information desired.
                         ki18n("Some text..."),
                         // The program homepage string.
                         "http://tutorial.com/",
                         // The bug report email address
                         "[email protected]");

    KCmdLineArgs::init( argc, argv, &aboutData );
    KApplication app;
    KGuiItem yesButton( i18n( "Hello" ), QString(),
                        i18n( "This is a tooltip" ),
                        i18n( "This is a WhatsThis help text." ) );
    KMessageBox::questionYesNo( 0, i18n( "Hello World" ),
                                i18n( "Hello" ), yesButton );
    return 0;
}

CMakeLists.txt

project (tutorial1)
find_package(KDE4 REQUIRED)
include (KDE4Defaults)
include_directories(${KDE4_INCLUDES})
set(tutorial1_SRCS main.cpp)
kde4_add_executable(tutorial1 ${tutorial1_SRCS})
target_link_libraries(tutorial1 ${KDE4_KDEUI_LIBS})
install(TARGETS tutorial1  ${INSTALL_TARGETS_DEFAULT_ARGS})

Now let's compile this without debugging symbols:

cmake . -DCMAKE_BUILD_TYPE=release && make -j4

We see that the resulting file is small:

# ll tutorial1
-rwxr-xr-x 1 root root 18133 Jul 11 18:07 tutorial1

With debugging symbols, the file is bigger:

cmake . -DCMAKE_BUILD_TYPE=debugfull && make
# ll tutorial1
-rwxr-xr-x 1 root root 260256 Jul 11 18:09 tutorial1