Bug 63883 Cannot configure option for enabling/disabling exclusion filters or custom output folders on a per project basis
Build M9 JDT/Core supports setting enablement for exclusion patterns and custom output folders on a per project basis. This isn't surfaced in the UI. There is only a global flag in workspace preferences.
org.eclipse.jdt.ui/ui/org/eclipse/jdt/internal/ui/preferences/BuildPathPreferencesBlock.java
addCheckBox(othersComposite, label, PREF_ENABLE_EXCLUSION_PATTERNS, enableDisableValues, 0);
		label= PreferencesMessages.getString("CompilerConfigurationBlock.enable_multiple_outputlocations.label"); 
		addCheckBox(othersComposite, label, PREF_ENABLE_MULTIPLE_OUTPUT_LOCATIONS, enableDisableValues, 0);
		
		return othersComposite;
	}
	
	/* (non-javadoc)
	 * Update fields and validate.
	 * @param changedKey Key that changed, or null, if all changed.
	 */	
	protected void validateSettings(String changedKey, String newValue) {
		if (changedKey != null) {
			return;
		} else {
			updateEnableStates();
		}		
		IStatus status= fResourceFilterStatus;
		fContext.statusChanged(status);
	}
	
	private void updateEnableStates() {
	}
	
	protected String[] getFullBuildDialogStrings(boolean workspaceSettings) {
		return null; 
	}	
	
}