It is not a project issue but a toolchain issue, I think. Reassign to code subcomponent. In Sun Studio (express), who
will be responsible for debugging gnu compiled code? Gdbgui module (which is currently disabled in SS) or dbxgui module?
Assigning to Vladimir V. for evaluation.

I'm not sure if gdb support is planned for SS EA. I've heard nothing about this.

Debugger field is invisible in toolchain panel, because SS hides it => unhide on SS side.
states of buttons is controlled on SS side as well

Take a look at this code in dbxgui in DbxActionHandlerFactory:

    @Override
    public boolean canHandle(ProjectActionEvent.Type type, Configuration conf) {
        if (!super.canHandle(type, conf)) {
            return false;
        }
        if (conf instanceof MakeConfiguration) {
            MakeConfiguration mc = (MakeConfiguration)conf;
            final CompilerSet compilerSet = mc.getCompilerSet().getCompilerSet();
            if (compilerSet == null) {
                return false;
            }
            return compilerSet.getTool(Tool.DebuggerTool) instanceof SunDebuggerTool;
        }
        return false;
    }

I believe it needs to recognize GNU tool chain and then the action (button) will get enabled.

Created attachment 89937 [details]
stack trace for DbxActionHandlerFactory.canHandle()

I put DbxActionHandlerFactory.canHandle under debugger, "compilerSet" always gets value "SunStudio_12.1",  so even I
added code to support GNUDebuggerTool, thing still does not work. the stack trace of debugger is attched.


        if (conf instanceof MakeConfiguration) {
            MakeConfiguration mc = (MakeConfiguration)conf;
            final CompilerSet compilerSet = mc.getCompilerSet().getCompilerSet();
            if (compilerSet == null) {
                return false;
            }
            return compilerSet.getTool(Tool.DebuggerTool) instanceof SunDebuggerTool ||
                    compilerSet.getTool(Tool.DebuggerTool) instanceof GNUDebuggerTool;

fixed in:
http://lessing.sfbay.sun.com/hg/toolshg/rev/d1a0cfbf884b

now DbxActionHandlerFactory handles all debug actions

Verified.