1. Fix for [Bug 191744] Switching build configurations should not save .cproject

2. Fix for [Bug 186380] [New Project Model] Saving project description is slow

build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Configuration.java

@@ -960,7 +960,7 @@ public class Configuration extends BuildObject implements IConfiguration, IBuild
 			LanguageSettingEntriesSerializer.serializeEntries(sourceEntries, el);
 		}
 		// I am clean now
-		isDirty = false;
+		setDirty(false);
 	}
 
 	/*

build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/dataprovider/ConfigurationDataProvider.java

@@ -100,8 +100,8 @@ public class ConfigurationDataProvider extends CConfigurationDataProvider implem
 		
 	}
 	static BuildConfigurationData writeConfiguration(ICConfigurationDescription des,
-			CConfigurationData base) throws CoreException {
+			BuildConfigurationData base) throws CoreException {
-		BuildConfigurationData appliedCfg = (BuildConfigurationData)base;
+		BuildConfigurationData appliedCfg = base;
 		ICStorageElement rootElement = des.getStorage(BUILD_SYSTEM_DATA_MODULE_NAME, true);
 		rootElement.clear();
 		rootElement.setAttribute(VERSION_ATTRIBUTE, ManagedBuildManager.getVersion().toString());
@@ -122,7 +122,7 @@ public class ConfigurationDataProvider extends CConfigurationDataProvider implem
 	protected CConfigurationData applyPreferences(
 			ICConfigurationDescription des, CConfigurationData base) throws CoreException{
 
-		BuildConfigurationData appliedCfg = writeConfiguration(des, base);
+		BuildConfigurationData appliedCfg = writeConfiguration(des, (BuildConfigurationData)base);
 		
 		IConfiguration cfg = ((BuildConfigurationData)base).getConfiguration();
 		try {
@@ -144,7 +144,15 @@ public class ConfigurationDataProvider extends CConfigurationDataProvider implem
 		if(des.isPreferenceConfiguration())
 			return applyPreferences(des, base);
 		
-		BuildConfigurationData appliedCfg = writeConfiguration(des, base);
+		BuildConfigurationData baseCfgData = (BuildConfigurationData)base;
+		IConfiguration baseCfg = baseCfgData.getConfiguration();
+		BuildConfigurationData appliedCfg;
+		if(context.getBaseConfigurationDataCacheState() && !baseCfg.isDirty()){
+			appliedCfg = baseCfgData;
+			context.setConfiguratoinDataModifiedState(false);
+		} else {
+			appliedCfg = writeConfiguration(des, baseCfgData);
+			context.setConfiguratoinDataModifiedState(true);
 			
 			IManagedBuildInfo info = getBuildInfo(des);
 			ManagedProject mProj = (ManagedProject)info.getManagedProject();
@@ -175,7 +183,7 @@ public class ConfigurationDataProvider extends CConfigurationDataProvider implem
 					break;
 				}
 			}
-		
+		}
 		return appliedCfg;
 	}
 	

core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/settings/model/IModificationContext.java

@@ -23,4 +23,14 @@ public interface IModificationContext {
 	void setEclipseProjectDescription(IProjectDescription eDes) throws CoreException;
 
 	void addWorkspaceRunnable(IWorkspaceRunnable runnable);
+	
+	/**
+	 * the CConfigurationDataProvider can call this method to indicate whether the
+	 * ICConfigurationDescription settings were changed 
+	 * @param modified
+	 */
+	void setConfiguratoinDataModifiedState(boolean modified);
+
+	boolean getBaseConfigurationDataCacheState();
+
 }

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CConfigurationDescriptionCache.java

@@ -32,7 +32,6 @@ import org.eclipse.cdt.core.settings.model.ICSettingObject;
 import org.eclipse.cdt.core.settings.model.ICSourceEntry;
 import org.eclipse.cdt.core.settings.model.ICStorageElement;
 import org.eclipse.cdt.core.settings.model.ICTargetPlatformSetting;
-import org.eclipse.cdt.core.settings.model.IModificationContext;
 import org.eclipse.cdt.core.settings.model.WriteAccessException;
 import org.eclipse.cdt.core.settings.model.extension.CBuildData;
 import org.eclipse.cdt.core.settings.model.extension.CConfigurationData;
@@ -60,6 +59,7 @@ public class CConfigurationDescriptionCache extends CDefaultConfigurationData
 	private List fChildList = new ArrayList();
 	private CConfigurationSpecSettings fSpecSettings;
 	private CConfigurationData fData;
+	private CConfigurationDescriptionCache fBaseCache;
 	private ICSourceEntry fProjSourceEntries[];
 	private StorableCdtVariables fMacros;
 	private boolean fDataLoadded;
@@ -105,11 +105,12 @@ public class CConfigurationDescriptionCache extends CDefaultConfigurationData
 //		fInitializing = false;
 	}
 
-	CConfigurationDescriptionCache(ICConfigurationDescription baseDescription, CConfigurationData base, CConfigurationSpecSettings settingsBase, CProjectDescription parent, ICStorageElement rootEl) throws CoreException {
+	CConfigurationDescriptionCache(ICConfigurationDescription baseDescription, CConfigurationData base, CConfigurationDescriptionCache baseCache, CConfigurationSpecSettings settingsBase, CProjectDescription parent, ICStorageElement rootEl) throws CoreException {
 		super(base.getId(), base.getName(), null);
 		fInitializing = true;
 		fParent = parent;
 		fSpecSettings = new CConfigurationSpecSettings(this, settingsBase, rootEl);
+		fSpecSettings.setModified(settingsBase.isModified());
 		fBaseDescription = baseDescription;
 		if(base instanceof CConfigurationDescriptionCache){
 			fData = ((CConfigurationDescriptionCache)base).getConfigurationData();
@@ -119,23 +120,17 @@ public class CConfigurationDescriptionCache extends CDefaultConfigurationData
 //			base = CProjectDescriptionManager.getInstance().applyData(this, baseDescription, base);
 //			fData = base;
 		} 
-//		fDataLoadded = true;
+		
-//		fName = fData.getName();
+		fBaseCache = baseCache;
-//		fId = fData.getId();
-//		
-//		copySettingsFrom(base, true);
-//		
-//		ICdtVariable vars[] = CdtVariableManager.getDefault().getVariables(this);
-//		fMacros = new StorableCdtVariables(vars, true);
-//		if(saving)
-//			fSpecSettings.serialize();
-//		
-//		fInitializing = false;
 	}
 	
-	void applyData(CSettingEntryFactory factory, IModificationContext context) throws CoreException{
+	CConfigurationDescriptionCache getBaseCache(){
-		if(fBaseDescription == null)
+		return fBaseCache;
-			return;
+	}
+	
+	boolean applyData(CSettingEntryFactory factory, SettingsContext context) throws CoreException{
+		boolean modified = true; 
+		if(fBaseDescription != null){
 		
 			fData = CProjectDescriptionManager.getInstance().applyData(this, fBaseDescription, fData, context, null);
 			fDataLoadded = true;
@@ -143,17 +138,26 @@ public class CConfigurationDescriptionCache extends CDefaultConfigurationData
 			fId = fData.getId();
 			fSettingsFactory = factory;
 			
+			if(context.getConfiguratoinDataModifiedState() || fBaseCache == null)
 				copySettingsFrom(fData, true);
+			else {
+				copySettingsFrom(fBaseCache, true);
+				modified = fSpecSettings.isModified();
+			}
 			
 			fSettingsFactory = null;
 			
 			ICdtVariable vars[] = CdtVariableManager.getDefault().getVariables(this);
 			fMacros = new StorableCdtVariables(vars, true);
-//		if(saving)
 			fSpecSettings.serialize();
+			fSpecSettings.setModified(false);
+		
+		}
 		
 		fBaseDescription = null;
-//		fInitializing = false;
+		fBaseCache = null;
+		
+		return modified;
 	}
 	
 	CSettingEntryFactory getSettingsFactory(){

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CConfigurationSpecSettings.java

@@ -488,10 +488,13 @@ public class CConfigurationSpecSettings implements ICSettingsStorage{
 		return fExtSettingsProvider.isModified();
 	}
 
-	void setModified(){
+	void setModified(boolean modified){
 		if(isReadOnly())
 			throw ExceptionFactory.createIsReadOnlyException();
-		fIsModified = true;
+		fIsModified = modified;
+	}
+	void setModified(){
+		setModified(true);
 	}
 	
 	private Map getSessionPropertiesMap(boolean create){

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescription.java

@@ -23,7 +23,6 @@ import org.eclipse.cdt.core.settings.model.ICSettingContainer;
 import org.eclipse.cdt.core.settings.model.ICSettingObject;
 import org.eclipse.cdt.core.settings.model.ICSettingsStorage;
 import org.eclipse.cdt.core.settings.model.ICStorageElement;
-import org.eclipse.cdt.core.settings.model.IModificationContext;
 import org.eclipse.cdt.core.settings.model.WriteAccessException;
 import org.eclipse.cdt.core.settings.model.extension.CConfigurationData;
 import org.eclipse.cdt.core.settings.model.util.CSettingEntryFactory;
@@ -206,15 +205,17 @@ public class CProjectDescription implements ICProjectDescription, ICDataProxyCon
 //		fIsLoadding = false;
 	}
 
-	void applyDatas(IModificationContext context){
+	boolean applyDatas(SettingsContext context){
 		if(!fIsReadOnly || !fIsApplying)
-			return;
+			return false;
 		
 		CSettingEntryFactory factory = new CSettingEntryFactory();
+		boolean modified = false;
 		for(Iterator iter = fCfgMap.values().iterator(); iter.hasNext();){
 			CConfigurationDescriptionCache cache = (CConfigurationDescriptionCache)iter.next();
 			try {
-				cache.applyData(factory, context);
+				if(cache.applyData(factory, context))
+					modified = true;
 			} catch (CoreException e) {
 				CCorePlugin.log(e);
 				e.printStackTrace();
@@ -227,6 +228,8 @@ public class CProjectDescription implements ICProjectDescription, ICDataProxyCon
 		factory.clear();
 		
 //		fIsApplying = false;
+		
+		return modified;
 	}
 	
 	
@@ -280,10 +283,12 @@ public class CProjectDescription implements ICProjectDescription, ICDataProxyCon
 				IInternalCCfgInfo cfgDes = (IInternalCCfgInfo)iter.next();
 				if(fIsReadOnly){
 					CConfigurationData baseData = cfgDes.getConfigurationData(false);
+					CConfigurationDescriptionCache baseCache = null;
 					if(baseData instanceof CConfigurationDescriptionCache){
-						baseData = ((CConfigurationDescriptionCache)baseData).getConfigurationData();
+						baseCache = (CConfigurationDescriptionCache)baseData;
+						baseData = baseCache.getConfigurationData();
 					}
-					CConfigurationDescriptionCache cache = new CConfigurationDescriptionCache((ICConfigurationDescription)cfgDes, baseData, cfgDes.getSpecSettings(), this, null);
+					CConfigurationDescriptionCache cache = new CConfigurationDescriptionCache((ICConfigurationDescription)cfgDes, baseData, baseCache, cfgDes.getSpecSettings(), this, null);
 					configurationCreated(cache);
 				} else {
 					CConfigurationData baseData = cfgDes.getConfigurationData(false);

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/CProjectDescriptionManager.java

@@ -69,7 +69,6 @@ import org.eclipse.cdt.core.settings.model.ICSettingsStorage;
 import org.eclipse.cdt.core.settings.model.ICSourceEntry;
 import org.eclipse.cdt.core.settings.model.ICStorageElement;
 import org.eclipse.cdt.core.settings.model.ICTargetPlatformSetting;
-import org.eclipse.cdt.core.settings.model.IModificationContext;
 import org.eclipse.cdt.core.settings.model.extension.CConfigurationData;
 import org.eclipse.cdt.core.settings.model.extension.CConfigurationDataProvider;
 import org.eclipse.cdt.core.settings.model.extension.CFileData;
@@ -1671,11 +1670,12 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 		return provider.loadConfiguration(des, monitor);
 	}
 	
-	CConfigurationData applyData(ICConfigurationDescription des, ICConfigurationDescription baseDescription, CConfigurationData base, IModificationContext context, IProgressMonitor monitor) throws CoreException {
+	CConfigurationData applyData(CConfigurationDescriptionCache des, ICConfigurationDescription baseDescription, CConfigurationData base, SettingsContext context, IProgressMonitor monitor) throws CoreException {
 		if(monitor == null)
 			monitor = new NullProgressMonitor();
 		
 		CConfigurationDataProvider provider = getProvider(des);
+		context.init(des);
 		return provider.applyConfiguration(des, baseDescription, base, context, monitor);
 	}
 
@@ -3095,8 +3095,10 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 	private CConfigurationDescriptionCache createPreferenceCache(ICConfigurationDescription des) throws CoreException{
 		IInternalCCfgInfo cfgDes = (IInternalCCfgInfo)des;
 		CConfigurationData baseData = cfgDes.getConfigurationData(false);
+		CConfigurationDescriptionCache baseCache = null;
 		if(baseData instanceof CConfigurationDescriptionCache){
-			baseData = ((CConfigurationDescriptionCache)baseData).getConfigurationData();
+			baseCache = (CConfigurationDescriptionCache)baseData;
+			baseData = baseCache.getConfigurationData();
 		}
 		CConfigurationSpecSettings settings = cfgDes.getSpecSettings();
 		ICStorageElement rootEl = getBuildSystemConfigPreferenceStorage(des.getBuildSystemId(), true, false);
@@ -3104,7 +3106,7 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 		rootParent.removeChild(rootEl);
 		ICStorageElement baseRootEl = settings.getRootStorageElement();
 		rootEl = rootParent.importChild(baseRootEl);
-		CConfigurationDescriptionCache cache = new CConfigurationDescriptionCache(des, baseData, cfgDes.getSpecSettings(), null, rootEl);
+		CConfigurationDescriptionCache cache = new CConfigurationDescriptionCache(des, baseData, baseCache, cfgDes.getSpecSettings(), null, rootEl);
 		CSettingEntryFactory factory = new CSettingEntryFactory();
 		SettingsContext context = new SettingsContext(null);
 		cache.applyData(factory, context);

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/SetCProjectDescriptionOperation.java

@@ -45,7 +45,7 @@ public class SetCProjectDescriptionOperation extends CModelOperation {
 		mngr.notifyListeners(event);
 		CProjectDescription fNewDescriptionCache = null;
 		SettingsContext context = new SettingsContext(project);
-		
+		boolean modified;
 		if(fSetDescription != null){
 			InternalXmlStorageElement el = null;
 			try {
@@ -63,10 +63,12 @@ public class SetCProjectDescriptionOperation extends CModelOperation {
 			fNewDescriptionCache = new CProjectDescription(fSetDescription, true, el, creating);
 			try {
 				mngr.setDescriptionApplying(project, fNewDescriptionCache);
-				fNewDescriptionCache.applyDatas(context);
+				modified = fNewDescriptionCache.applyDatas(context);
 			} finally {
 				mngr.clearDescriptionApplying(project);
 			}
+		} else {
+			modified = fOldDescriptionCache != null;
 		}
 		
 		ICDescriptionDelta delta = mngr.createDelta(fNewDescriptionCache, fOldDescriptionCache);
@@ -115,8 +117,11 @@ public class SetCProjectDescriptionOperation extends CModelOperation {
 		mngr.notifyListeners(event);
 
 		try {
-			if(fNewDescriptionCache != null && !CProjectDescriptionManager.checkFlags(fFlags, ICProjectDescriptionManager.SET_NO_SERIALIZE))
+			if(fNewDescriptionCache != null && !CProjectDescriptionManager.checkFlags(fFlags, ICProjectDescriptionManager.SET_NO_SERIALIZE)){
+				if(modified || isPersistentCoreSettingChanged(event)){
 					context.addWorkspaceRunnable(mngr.createDesSerializationRunnable(fNewDescriptionCache));
+				}
+			}
 			IWorkspaceRunnable toRun = context.createOperationRunnable();
 			
 			if(toRun != null)
@@ -126,6 +131,23 @@ public class SetCProjectDescriptionOperation extends CModelOperation {
 		}
 	}
 	
+	private static boolean isPersistentCoreSettingChanged(CProjectDescriptionEvent event){
+		ICDescriptionDelta delta = event.getProjectDelta();
+		if(delta == null)
+			return false;
+		if(delta.getDeltaKind() != ICDescriptionDelta.CHANGED)
+			return true;
+		
+		if(delta.getChildren().length != 0)
+			return true;
+		
+		int flags = delta.getChangeFlags(); 
+		if(flags != 0 && flags != ICDescriptionDelta.ACTIVE_CFG)
+			return true;
+		
+		return false;
+	}
+	
 	public boolean isReadOnly() {
 		return false;
 	}

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/settings/model/SettingsContext.java

@@ -22,6 +22,8 @@ public final class SettingsContext implements IModificationContext{
 	private IProjectDescription fEDes;
 	private IProject fProject;
 	private CompositeWorkspaceRunnable fRunnable;
+	private boolean fCfgDataModifyState;
+	private boolean fCfgDataCacheState;
 	
 	SettingsContext(IProject project){
 		fProject = project;
@@ -31,6 +33,11 @@ public final class SettingsContext implements IModificationContext{
 		return fProject;
 	}
 	
+	void init(CConfigurationDescriptionCache cfg){
+		fCfgDataModifyState = true;
+		fCfgDataCacheState = cfg.getBaseCache() != null;
+	}
+
 	IProjectDescription getEclipseProjectDescription(boolean create) throws CoreException{
 		IProjectDescription eDes = fEDes;
 		if(eDes == null && create){
@@ -89,4 +96,16 @@ public final class SettingsContext implements IModificationContext{
 		}
 		return null;
 	}
+
+	public boolean getBaseConfigurationDataCacheState() {
+		return fCfgDataCacheState;
+	}
+
+	public void setConfiguratoinDataModifiedState(boolean modified) {
+		fCfgDataModifyState = modified;
+	}
+	
+	public boolean getConfiguratoinDataModifiedState(){
+		return fCfgDataModifyState;
+	}
 }