bug 398056: Regression: LanguageSettingsProviders can get enabled unexpectedly on project-import when they should not

build/org.eclipse.cdt.managedbuilder.core.tests/tests/org/eclipse/cdt/managedbuilder/core/tests/ManagedBuildCoreTests20.java

@@ -10,8 +10,6 @@
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.core.tests;
 
-import java.io.File;
-import java.io.IOException;
 import java.util.Arrays;
 import java.util.Map;
 import java.util.Properties;
@@ -24,7 +22,6 @@ import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.parser.IScannerInfo;
 import org.eclipse.cdt.core.parser.IScannerInfoChangeListener;
 import org.eclipse.cdt.core.parser.IScannerInfoProvider;
-import org.eclipse.cdt.internal.core.language.settings.providers.LanguageSettingsScannerInfoProvider;
 import org.eclipse.cdt.managedbuilder.core.BuildException;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
 import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
@@ -201,26 +198,6 @@ public class ManagedBuildCoreTests20 extends TestCase {
 	}
 
 
-	/**
-	 * Convert path to OS specific representation
-	 */
-	private String toOSLocation(String path) {
-		File file = new File(path);
-		try {
-			path = file.getCanonicalPath();
-		} catch (IOException e) {
-		}
-		
-		return path;
-	}
-
-	/**
-	 * Convert path to OS specific representation
-	 */
-	private String toOSString(String path) {
-		return new Path(path).toOSString();
-	}
-
 	/**
 	 * The purpose of this test is to exercise the build path info interface.
 	 * To get to that point, a new project/config has to be created in the test
@@ -241,38 +218,18 @@ public class ManagedBuildCoreTests20 extends TestCase {
 		}
 
 		//These are the expected path settings
-		IPath buildCWD = project.getLocation().append("Sub Config");
+		 final String[] expectedPaths = new String[5];
 
-		final String[] expectedPaths;
+		 // This first path is a built-in, so it will not be manipulated by build manager
-		if (new Path("C:\\home\\tester/include").isAbsolute()) {
+		 expectedPaths[0] = (new Path("/usr/include")).toOSString();
-			// Windows
+		 expectedPaths[1] = (new Path("/opt/gnome/include")).toOSString();
-			expectedPaths = new String[] {
+		 IPath path = new Path("C:\\home\\tester/include");
-					toOSLocation("/usr/include"),
+		 if(path.isAbsolute()) // for win32 path is treated as absolute
-					toOSLocation("/opt/gnome/include"),
+			 expectedPaths[2] = path.toOSString();
-					toOSLocation("C:\\home\\tester/include"),
+		 else // for Linux path is relative
-					// relative paths from MBS will make 3 entries
+			 expectedPaths[2] = project.getLocation().append("Sub Config").append(path).toOSString();
-					project.getLocation().append("includes").toOSString(),
+		 expectedPaths[3] = project.getLocation().append( "includes" ).toOSString();
-					buildCWD.append("includes").toOSString(),
+		 expectedPaths[4] = (new Path("/usr/gnu/include")).toOSString();
-					toOSString("includes"),
-					"/usr/gnu/include", // Not converted to OS string due to being flagged as ICSettingEntry.RESOLVED
-			};
-		} else {
-			// Unix
-			expectedPaths = new String[] {
-					toOSLocation("/usr/include"),
-					toOSLocation("/opt/gnome/include"),
-					// on unix "C:\\home\\tester/include" is relative path
-					// looks like nonsense but has to be this way as MBS converts entry to keep "Sub Config/C:\\home\\tester/include" in its storage
-					project.getLocation().append("Sub Config/C:\\home\\tester/include").toOSString(),
-					buildCWD.append("Sub Config/C:\\home\\tester/include").toOSString(),
-					toOSString("Sub Config/C:\\home\\tester/include"),
-					// relative paths from MBS will make 3 entries
-					project.getLocation().append("includes").toOSString(),
-					buildCWD.append("includes").toOSString(),
-					toOSString("includes"),
-					"/usr/gnu/include", // Not converted to OS string due to being flagged as ICSettingEntry.RESOLVED
-			};
-		}
 
 		// Create a new managed project based on the sub project type
 		IProjectType projType = ManagedBuildManager.getExtensionProjectType("test.sub");
@@ -324,7 +281,6 @@ public class ManagedBuildCoreTests20 extends TestCase {
 		// Find the first IScannerInfoProvider that supplies build info for the project
 		IScannerInfoProvider provider = CCorePlugin.getDefault().getScannerInfoProvider(project);
 		assertNotNull(provider);
-		assertTrue(provider instanceof LanguageSettingsScannerInfoProvider);
 
 		// Now subscribe (note that the method will be called after a change
 		provider.subscribe(project, new IScannerInfoChangeListener () {

core/org.eclipse.cdt.core/model/org/eclipse/cdt/core/language/settings/providers/ScannerDiscoveryLegacySupport.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2011 Andrew Gvozdev and others.
+ * Copyright (c) 2009, 2013 Andrew Gvozdev and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -23,6 +23,8 @@ import org.eclipse.cdt.core.settings.model.ICProjectDescription;
 import org.eclipse.cdt.internal.core.LocalProjectScope;
 import org.eclipse.cdt.internal.core.language.settings.providers.LanguageSettingsExtensionManager;
 import org.eclipse.cdt.internal.core.language.settings.providers.LanguageSettingsProvidersSerializer;
+import org.eclipse.cdt.internal.core.language.settings.providers.ScannerInfoExtensionLanguageSettingsProvider;
+import org.eclipse.cdt.internal.core.settings.model.CProjectDescriptionManager;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.runtime.preferences.InstanceScope;
 import org.osgi.service.prefs.BackingStoreException;
@@ -42,6 +44,8 @@ public class ScannerDiscoveryLegacySupport {
 	public static final String USER_LANGUAGE_SETTINGS_PROVIDER_ID = "org.eclipse.cdt.ui.UserLanguageSettingsProvider"; //$NON-NLS-1$
 	/** ID of MBS language settings provider (from org.eclipse.cdt.managedbuilder.core) */
 	public static final String MBS_LANGUAGE_SETTINGS_PROVIDER_ID = "org.eclipse.cdt.managedbuilder.core.MBSLanguageSettingsProvider"; //$NON-NLS-1$
+	/** ID of ScannerInfo language settings provider wrapping ScannerInfoProvider defined by org.eclipse.cdt.core.ScannerInfoProvider extension point */
+	private static final String SI_LANGUAGE_SETTINGS_PROVIDER_ID = "org.eclipse.cdt.core.LegacyScannerInfoLanguageSettingsProvider"; //$NON-NLS-1$
 
 	private static String DISABLE_LSP_PREFERENCE = "language.settings.providers.disabled"; //$NON-NLS-1$
 	//	the default for project needs to be "disabled" - for legacy projects to be open with old SD enabled for MBS provider
@@ -156,15 +160,60 @@ public class ScannerDiscoveryLegacySupport {
 	}
 
 	/**
-	 * Return list containing MBS and User provider. Used to initialize for unaware tool-chains (backward compatibility).
+	 * Return list containing User provider and one of wrapper providers to support legacy projects (backward compatibility).
+	 * 
+	 * @noreference This is internal helper method to support compatibility with previous versions
+	 * which is not intended to be referenced by clients.
+	 * @since 5.5
+	 */
+	public static String[] getDefaultProviderIdsLegacy(ICConfigurationDescription cfgDescription) {
+		boolean useScannerInfoProviderExtension = new ScannerInfoExtensionLanguageSettingsProvider().getScannerInfoProvider(cfgDescription) != null;
+		if (useScannerInfoProviderExtension) {
+			return new String[] {USER_LANGUAGE_SETTINGS_PROVIDER_ID, SI_LANGUAGE_SETTINGS_PROVIDER_ID};
+		}
+		if (CProjectDescriptionManager.getInstance().isNewStyleCfg(cfgDescription)) {
+			return new String[] {USER_LANGUAGE_SETTINGS_PROVIDER_ID, MBS_LANGUAGE_SETTINGS_PROVIDER_ID};
+		}
+		return null;
+
+	}
+	
+	/**
+	 * Checks if the provider is applicable for configuration from backward compatibility point of view
+	 * 
+	 * @noreference This is internal helper method to support compatibility with previous versions
+	 * which is not intended to be referenced by clients.
+	 * @since 5.5
+	 */
+	public static boolean isProviderCompatible(String providerId, ICConfigurationDescription cfgDescription) {
+		if (cfgDescription != null) {
+			boolean useScannerInfoProviderExtension = new ScannerInfoExtensionLanguageSettingsProvider().getScannerInfoProvider(cfgDescription) != null;
+			if (SI_LANGUAGE_SETTINGS_PROVIDER_ID.equals(providerId)) {
+				return useScannerInfoProviderExtension;
+			}
+
+			if (MBS_LANGUAGE_SETTINGS_PROVIDER_ID.equals(providerId)) {
+				boolean isNewStyleCfg = CProjectDescriptionManager.getInstance().isNewStyleCfg(cfgDescription);
+				return !useScannerInfoProviderExtension && isNewStyleCfg;
+			}
+		}
+
+		return true;
+	}
+
+	/**
+	 * Return list containing User and MBS providers. Used to initialize older MBS tool-chains (backward compatibility).
+	 * 
+	 * @noreference This is internal helper method to support compatibility with previous versions
+	 * which is not intended to be referenced by clients.
 	 */
 	public static List<ILanguageSettingsProvider> getDefaultProvidersLegacy() {
 		List<ILanguageSettingsProvider> providers = new ArrayList<ILanguageSettingsProvider>(2);
-		ILanguageSettingsProvider provider = LanguageSettingsExtensionManager.getExtensionProviderCopy((ScannerDiscoveryLegacySupport.USER_LANGUAGE_SETTINGS_PROVIDER_ID), false);
+		ILanguageSettingsProvider provider = LanguageSettingsExtensionManager.getExtensionProviderCopy((USER_LANGUAGE_SETTINGS_PROVIDER_ID), false);
 		if (provider != null) {
 			providers.add(provider);
 		}
-		providers.add(LanguageSettingsProvidersSerializer.getWorkspaceProvider(ScannerDiscoveryLegacySupport.MBS_LANGUAGE_SETTINGS_PROVIDER_ID));
+		providers.add(LanguageSettingsProvidersSerializer.getWorkspaceProvider(MBS_LANGUAGE_SETTINGS_PROVIDER_ID));
 		return providers;
 	}
 

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/settings/providers/LanguageSettingsProvidersSerializer.java

@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2009, 2011 Andrew Gvozdev and others.
+ * Copyright (c) 2009, 2013 Andrew Gvozdev and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -82,7 +82,7 @@ public class LanguageSettingsProvidersSerializer {
 	public static final String JOB_FAMILY_SERIALIZE_LANGUAGE_SETTINGS_WORKSPACE = "CDT_JOB_FAMILY_SERIALIZE_LANGUAGE_SETTINGS_WORKSPACE"; //$NON-NLS-1$
 
 	private static final String PREFERENCE_WORSPACE_PROVIDERS_SET = "language.settings.providers.workspace.prefs.toggle"; //$NON-NLS-1$
-	private static final String CPROJECT_STORAGE_MODULE = "org.eclipse.cdt.core.LanguageSettingsProviders"; //$NON-NLS-1$
+	private static final String CPROJECT_STORAGE_MODULE_LANGUAGE_SETTINGS_PROVIDERS = "org.eclipse.cdt.core.LanguageSettingsProviders"; //$NON-NLS-1$
 	private static final String STORAGE_WORKSPACE_LANGUAGE_SETTINGS = "language.settings.xml"; //$NON-NLS-1$
 	private static final String STORAGE_PROJECT_PATH = ".settings/language.settings.xml"; //$NON-NLS-1$
 
@@ -827,8 +827,13 @@ public class LanguageSettingsProvidersSerializer {
 	public static void serializeLanguageSettings(ICProjectDescription prjDescription) throws CoreException {
 		IProject project = prjDescription.getProject();
 		try {
-			// Using side effect of adding the module to the storage
+			// Add the storage module to .cpoject and persist on disk as a side effect of adding
-			prjDescription.getStorage(CPROJECT_STORAGE_MODULE, true);
+			prjDescription.getStorage(CPROJECT_STORAGE_MODULE_LANGUAGE_SETTINGS_PROVIDERS, true);
+			if (!ScannerDiscoveryLegacySupport.isLanguageSettingsProvidersFunctionalityDefined(project)) {
+				// set the flag if was not previously set by the user - to the default value
+				ScannerDiscoveryLegacySupport.setLanguageSettingsProvidersFunctionalityEnabled(project,
+						ScannerDiscoveryLegacySupport.isLanguageSettingsProvidersFunctionalityEnabled(project));
+			}
 		} catch (CoreException e) {
 			CCorePlugin.log("Internal error while trying to serialize language settings", e); //$NON-NLS-1$
 		}
@@ -1125,7 +1130,9 @@ public class LanguageSettingsProvidersSerializer {
 	public static void loadLanguageSettings(ICProjectDescription prjDescription) {
 		IProject project = prjDescription.getProject();
 		IFile storeInPrjArea = getStoreInProjectArea(project);
-		if (storeInPrjArea.exists()) {
+		boolean isStoreInProjectAreaExist = storeInPrjArea.exists();
+		boolean enableLSP = isStoreInProjectAreaExist;
+		if (isStoreInProjectAreaExist) {
 			Document doc = null;
 			try {
 				doc = XmlUtil.loadXml(storeInPrjArea);
@@ -1150,19 +1157,18 @@ public class LanguageSettingsProvidersSerializer {
 				CCorePlugin.log("Can't load preferences from file " + storeInPrjArea.getLocation(), e); //$NON-NLS-1$
 			}
 
-		} else {
+		} else { // Storage in project area does not exist
-			// Storage in project area does not exist
+			ICStorageElement lspStorageModule = null;
-			ICStorageElement storageElement = null;
 			try {
-				storageElement = prjDescription.getStorage(CPROJECT_STORAGE_MODULE, false);
+				lspStorageModule = prjDescription.getStorage(CPROJECT_STORAGE_MODULE_LANGUAGE_SETTINGS_PROVIDERS, false);
 			} catch (CoreException e) {
 				String msg = "Internal error while trying to load language settings"; //$NON-NLS-1$
 				CCorePlugin.log(msg, e);
 			}
 
-			if (storageElement != null) {
+			// set default providers defined in the tool-chain
-				// set default providers defined in the tool-chain
+			for (ICConfigurationDescription cfgDescription : prjDescription.getConfigurations()) {
-				for (ICConfigurationDescription cfgDescription : prjDescription.getConfigurations()) {
+				if (cfgDescription instanceof ILanguageSettingsProvidersKeeper) {
 					String[] ids = ((ILanguageSettingsProvidersKeeper) cfgDescription).getDefaultLanguageSettingsProvidersIds();
 					if (ids != null) {
 						List<ILanguageSettingsProvider> providers = new ArrayList<ILanguageSettingsProvider>(ids.length);
@@ -1176,23 +1182,16 @@ public class LanguageSettingsProvidersSerializer {
 						((ILanguageSettingsProvidersKeeper) cfgDescription).setLanguageSettingProviders(providers);
 					}
 				}
-
-			} else {
-				// Older existing legacy projects unaware of Language Settings Providers and their persistence store
-				ICConfigurationDescription[] cfgDescriptions = prjDescription.getConfigurations();
-				for (ICConfigurationDescription cfgDescription : cfgDescriptions) {
-					if (cfgDescription instanceof ILanguageSettingsProvidersKeeper) {
-						((ILanguageSettingsProvidersKeeper) cfgDescription).setLanguageSettingProviders(ScannerDiscoveryLegacySupport.getDefaultProvidersLegacy());
-					}
-				}
-			}
-			
-			if (!ScannerDiscoveryLegacySupport.isLanguageSettingsProvidersFunctionalityDefined(project)) {
-				// if not yet defined by user - set preference to tell if this is legacy .cproject (i.e. no LSP storageElement)
-				ScannerDiscoveryLegacySupport.setLanguageSettingsProvidersFunctionalityEnabled(project, storageElement != null);
 			}
 
+			enableLSP = lspStorageModule != null;
 		}
+
+		if (!ScannerDiscoveryLegacySupport.isLanguageSettingsProvidersFunctionalityDefined(project)) {
+			// set the flag if was not previously set by the user
+			ScannerDiscoveryLegacySupport.setLanguageSettingsProvidersFunctionalityEnabled(project, enableLSP);
+		}
+
 	}
 
 	/**

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/language/settings/providers/ScannerInfoExtensionLanguageSettingsProvider.java

@@ -0,0 +1,158 @@
+/*******************************************************************************
+ * Copyright (c) 2013, 2013 Andrew Gvozdev and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     Andrew Gvozdev - Initial API and implementation
+ *******************************************************************************/
+package org.eclipse.cdt.internal.core.language.settings.providers;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.Map;
+import java.util.Map.Entry;
+import java.util.TreeMap;
+
+import org.eclipse.cdt.core.AbstractCExtension;
+import org.eclipse.cdt.core.CCorePlugin;
+import org.eclipse.cdt.core.language.settings.providers.LanguageSettingsBaseProvider;
+import org.eclipse.cdt.core.parser.IExtendedScannerInfo;
+import org.eclipse.cdt.core.parser.IScannerInfo;
+import org.eclipse.cdt.core.parser.IScannerInfoProvider;
+import org.eclipse.cdt.core.settings.model.ICConfigExtensionReference;
+import org.eclipse.cdt.core.settings.model.ICConfigurationDescription;
+import org.eclipse.cdt.core.settings.model.ICLanguageSettingEntry;
+import org.eclipse.cdt.core.settings.model.ICSettingEntry;
+import org.eclipse.cdt.core.settings.model.util.CDataUtil;
+import org.eclipse.cdt.core.settings.model.util.CExtensionUtil;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IConfigurationElement;
+
+/**
+ * Wrapper class intended to provide backward compatibility with ScannerInfoProvider defined by org.eclipse.cdt.core.ScannerInfoProvider extension point
+ */
+public class ScannerInfoExtensionLanguageSettingsProvider extends LanguageSettingsBaseProvider {
+	@Override
+	public List<ICLanguageSettingEntry> getSettingEntries(ICConfigurationDescription cfgDescription, IResource rc, String languageId) {
+		List<ICLanguageSettingEntry> entries = new ArrayList<ICLanguageSettingEntry>();
+		IScannerInfoProvider scannerInfoProvider = getScannerInfoProvider(cfgDescription);
+		if (scannerInfoProvider != null) {
+			IScannerInfo si = scannerInfoProvider.getScannerInformation(rc);
+			if (si != null) {
+				if (si instanceof IExtendedScannerInfo) {
+					addLocalIncludePaths(entries, (IExtendedScannerInfo) si);
+				}
+	
+				addSystemIncludePaths(entries, si);
+				addDefinedSymbols(entries, si);
+	
+				if (si instanceof IExtendedScannerInfo) {
+					addIncludeFiles(entries, (IExtendedScannerInfo) si);
+					addMacroFiles(entries, (IExtendedScannerInfo) si);
+				}
+	
+				if (!entries.isEmpty()) {
+					return LanguageSettingsSerializableStorage.getPooledList(entries);
+				}
+			}
+		}
+		return null;
+	}
+
+	/**
+	 * Return ScannerInfoProvider defined in configuration metadata in .cproject.
+	 * 
+	 * @param cfgDescription - configuration description.
+	 * @return an instance of ScannerInfoProvider or {@code null}.
+	 */
+	public IScannerInfoProvider getScannerInfoProvider(ICConfigurationDescription cfgDescription) {
+		if (cfgDescription == null) {
+			return null;
+		}
+
+		IScannerInfoProvider scannerInfoProvider = null;
+		ICConfigExtensionReference[] refs = cfgDescription.get(CCorePlugin.BUILD_SCANNER_INFO_UNIQ_ID);
+		if (refs != null && refs.length > 0) {
+			ICConfigExtensionReference ref = refs[0];
+			try {
+				AbstractCExtension cExtension = null;
+				IConfigurationElement el = CExtensionUtil.getFirstConfigurationElement(ref, "cextension", false); //$NON-NLS-1$
+				cExtension = (AbstractCExtension)el.createExecutableExtension("run"); //$NON-NLS-1$
+				cExtension.setExtensionReference(ref);
+				cExtension.setProject(ref.getConfiguration().getProjectDescription().getProject());
+				if (cExtension instanceof IScannerInfoProvider) {
+					scannerInfoProvider = (IScannerInfoProvider) cExtension;
+				}
+			} catch (CoreException e) {
+				CCorePlugin.log(e);
+			}
+		}
+		return scannerInfoProvider;
+	}
+
+	/**
+	 * Add local include paths to the list of entries.
+	 */
+	private void addLocalIncludePaths(List<ICLanguageSettingEntry> entries, IExtendedScannerInfo esi) {
+		String[] localIncludePaths = esi.getLocalIncludePath();
+		if (localIncludePaths != null) {
+			for (String path : localIncludePaths) {
+				entries.add(CDataUtil.createCIncludePathEntry(path, ICSettingEntry.LOCAL));
+			}
+		}
+	}
+
+	/**
+	 * Add system include paths to the list of entries.
+	 */
+	private void addSystemIncludePaths(List<ICLanguageSettingEntry> entries, IScannerInfo si) {
+		String[] includePaths = si.getIncludePaths();
+		if (includePaths != null) {
+			for (String path : includePaths) {
+				entries.add(CDataUtil.createCIncludePathEntry(path, 0));
+			}
+		}
+	}
+
+	/**
+	 * Add defined macros to the list of entries.
+	 */
+	private void addDefinedSymbols(List<ICLanguageSettingEntry> entries, IScannerInfo si) {
+		Map<String, String> definedSymbols = si.getDefinedSymbols();
+		if (definedSymbols != null) {
+			for (Entry<String, String> entry : new TreeMap<String, String>(definedSymbols).entrySet()) {
+				String name = entry.getKey();
+				String value = entry.getValue();
+				entries.add(CDataUtil.createCMacroEntry(name, value, 0));
+			}
+		}
+	}
+
+	/**
+	 * Add include files to the list of entries.
+	 */
+	private void addIncludeFiles(List<ICLanguageSettingEntry> entries, IExtendedScannerInfo esi) {
+		String[] includeFiles = esi.getIncludeFiles();
+		if (includeFiles != null) {
+			for (String path : includeFiles) {
+				entries.add(CDataUtil.createCIncludeFileEntry(path, 0));
+			}
+		}
+	}
+
+	/**
+	 * Add macro files to the list of entries.
+	 */
+	private void addMacroFiles(List<ICLanguageSettingEntry> entries, IExtendedScannerInfo esi) {
+		String[] macroFiles = esi.getMacroFiles();
+		if (macroFiles != null) {
+			for (String path : macroFiles) {
+				entries.add(CDataUtil.createCMacroFileEntry(path, 0));
+			}
+		}
+	}
+}

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

@@ -52,6 +52,7 @@ import javax.xml.transform.stream.StreamResult;
 import org.eclipse.cdt.core.CCorePlugin;
 import org.eclipse.cdt.core.language.settings.providers.ILanguageSettingsProvider;
 import org.eclipse.cdt.core.language.settings.providers.ILanguageSettingsProvidersKeeper;
+import org.eclipse.cdt.core.language.settings.providers.ScannerDiscoveryLegacySupport;
 import org.eclipse.cdt.core.model.CModelException;
 import org.eclipse.cdt.core.model.ICElement;
 import org.eclipse.cdt.core.model.ICElementDelta;
@@ -1141,7 +1142,15 @@ public class CProjectDescriptionManager implements ICProjectDescriptionManager {
 			monitor = new NullProgressMonitor();
 
 		CConfigurationDataProvider provider = getProvider(des);
-		return provider.loadConfiguration(des, monitor);
+		CConfigurationData data = provider.loadConfiguration(des, monitor);
+
+		if (des instanceof ILanguageSettingsProvidersKeeper && ! des.isPreferenceConfiguration()) {
+			String[] defaultIds = ((ILanguageSettingsProvidersKeeper) des).getDefaultLanguageSettingsProvidersIds();
+			if (defaultIds == null) {
+				((ILanguageSettingsProvidersKeeper) des).setDefaultLanguageSettingsProvidersIds(ScannerDiscoveryLegacySupport.getDefaultProviderIdsLegacy(des));
+			}
+		}
+		return data;
 	}
 
 	CConfigurationData applyData(CConfigurationDescriptionCache des, ICConfigurationDescription baseDescription, CConfigurationData base, SettingsContext context, IProgressMonitor monitor) throws CoreException {

core/org.eclipse.cdt.core/plugin.properties

@@ -132,4 +132,5 @@ CProjectStorageType.separatefile.name = Xml Storage (Separate Files)
 scannerInfoProvider2.name = Scanner Info Provider
 efsExtensionProvider.name = EFSExtensionProvider
 refreshExclusionFactory.name = Refresh Exclusion Factory
-uncPathConverter.name = UNC Path Converter
+uncPathConverter.name = UNC Path Converter
+ScannerInfoExtensionLanguageSettingsProvider.name=Contributed ScannerInfo Entries

core/org.eclipse.cdt.core/plugin.xml

@@ -2,7 +2,7 @@
 <?eclipse version="3.0"?>
 <plugin>
 
-    
+
 <!-- =================================================================================== -->
 <!-- Obsolete extension point no longer in use, will be remove.                          -->
 <!-- =================================================================================== -->
@@ -782,5 +782,13 @@
             factoryClass="org.eclipse.cdt.internal.core.resources.ResourceExclusionFactory">
       </exclusionFactory>
    </extension>
+   <extension
+         point="org.eclipse.cdt.core.LanguageSettingsProvider">
+      <provider
+            class="org.eclipse.cdt.internal.core.language.settings.providers.ScannerInfoExtensionLanguageSettingsProvider"
+            id="org.eclipse.cdt.core.LegacyScannerInfoLanguageSettingsProvider"
+            name="%ScannerInfoExtensionLanguageSettingsProvider.name">
+      </provider>
+   </extension>
 
 </plugin>

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/language/settings/providers/LanguageSettingsProviderTab.java

@@ -926,7 +926,7 @@ public class LanguageSettingsProviderTab extends AbstractCPropertyTab {
 
 		for (ILanguageSettingsProvider provider : allAvailableProvidersSet) {
 			String id = provider.getId();
-			if (!idsList.contains(id)) {
+			if (!idsList.contains(id) && ScannerDiscoveryLegacySupport.isProviderCompatible(id, cfgDescription)) {
 				providers.add(provider);
 				idsList.add(id);
 			}

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/ui/newui/ManageConfigDialog.java

@@ -276,11 +276,17 @@ public class ManageConfigDialog extends Dialog {
 		for (int i=0; i<cfgds.length; i++ ) {
 			TableItem t = new TableItem(table, 0);
 			t.setText(0, cfgds[i].getName());
-			t.setText(1, cfgds[i].getDescription());
+			String description = cfgds[i].getDescription();
+			if (description == null) {
+				description = ""; //$NON-NLS-1$
+			}
+			t.setText(1, description);
 			t.setText(2, cfgds[i].isActive() ? Messages.ManageConfigDialog_5 : ""); //$NON-NLS-1$ 
 			t.setData(cfgds[i]);
 		}
-		if (table.getItemCount() > 0) table.select(0);
+		if (table.getItemCount() > 0) {
+			table.select(0);
+		}
 		table.setFocus();
 		updateButtons();
 	}