< Guidelines and HOWTOs‎ | Debugging
Revision as of 17:03, 11 July 2009 by *>Tstaerk

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 write an application that crashes:


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

using namespace std;

int main (int argc, char *argv[])
    KAboutData aboutData( "tutorial1", 0, ki18n("Tutorial 1"), "1.0",
                          ki18n("Displays a KMessageBox popup"),
                          ki18n("(c) 2009"), ki18n("Some text..."),
                          "[email protected]");

    KCmdLineArgs::init( argc, argv, &aboutData );
    KApplication app;

    KMessageBox::questionYesNo( 0, i18n( "Hello World" ) );
    int* i;
    cout << "i is at " << i << " value " << *i << endl;
    cout << "i is at " << i << " value " << *i << endl;
    // We now try to read from memory address 0x400891
    cout << "i is at " << i << " value " << *i << endl;

    return 0;


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

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 18879 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 256622 Jul 11 18:09 tutorial1

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