diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FileInfoModification.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FileInfoModification.java
index 338f70eed6d..cbdaccd987e 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FileInfoModification.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FileInfoModification.java
@@ -14,7 +14,11 @@ import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.eclipse.cdt.managedbuilder.core.IFileInfo;
+import org.eclipse.cdt.managedbuilder.core.IFolderInfo;
+import org.eclipse.cdt.managedbuilder.core.IResourceInfo;
 import org.eclipse.cdt.managedbuilder.core.ITool;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
 import org.eclipse.cdt.managedbuilder.internal.core.ResourceConfiguration;
 import org.eclipse.cdt.managedbuilder.internal.core.Tool;
 import org.eclipse.cdt.managedbuilder.tcmodification.IFileInfoModification;
@@ -81,4 +85,30 @@ public class FileInfoModification extends
 		return fProject;
 	}
 
+	public void restoreDefaults() {
+//		3.per-file : change to the tool from the parent folder's tool-chain suitable
+//		for the given file. NOTE: the custom build step tool should be preserved!
+		ResourceConfiguration rcInfo = (ResourceConfiguration)getResourceInfo();
+		IFolderInfo parentFo = rcInfo.getParentFolderInfo();
+		String ext = rcInfo.getPath().getFileExtension();
+		if(ext == null)
+			ext = "";
+
+		ITool tool = parentFo.getToolFromInputExtension(ext);
+		ITool realTool = ManagedBuildManager.getRealTool(tool);
+		boolean add = true;
+		
+		ITool[] curTools = getProjectTools();
+		for(int i = 0; i < curTools.length; i++){
+			ITool cur = curTools[i];
+			if(ManagedBuildManager.getRealTool(cur) == realTool){
+				add = false;
+			} else if (!cur.getCustomBuildStep()){
+				changeProjectTools(cur, null);
+			}
+		}
+		
+		if(add)
+			changeProjectTools(null, tool);
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FolderInfoModification.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FolderInfoModification.java
index e3ec3aa74e7..105e8e122c7 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FolderInfoModification.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/tcmodification/FolderInfoModification.java
@@ -22,6 +22,10 @@ import java.util.Set;
 import java.util.SortedMap;
 import java.util.TreeMap;
 
+import org.eclipse.cdt.managedbuilder.core.BuildException;
+import org.eclipse.cdt.managedbuilder.core.IBuilder;
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IFolderInfo;
 import org.eclipse.cdt.managedbuilder.core.IManagedProject;
 import org.eclipse.cdt.managedbuilder.core.IResourceInfo;
 import org.eclipse.cdt.managedbuilder.core.ITool;
@@ -29,8 +33,10 @@ import org.eclipse.cdt.managedbuilder.core.IToolChain;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
 import org.eclipse.cdt.managedbuilder.internal.core.FolderInfo;
 import org.eclipse.cdt.managedbuilder.internal.core.IRealBuildObjectAssociation;
+import org.eclipse.cdt.managedbuilder.internal.core.ResourceInfo;
 import org.eclipse.cdt.managedbuilder.internal.core.Tool;
 import org.eclipse.cdt.managedbuilder.internal.core.ToolChain;
+import org.eclipse.cdt.managedbuilder.internal.dataprovider.ConfigurationDataProvider;
 import org.eclipse.cdt.managedbuilder.internal.tcmodification.ToolChainModificationManager.ConflictMatchSet;
 import org.eclipse.cdt.managedbuilder.tcmodification.CompatibilityStatus;
 import org.eclipse.cdt.managedbuilder.tcmodification.IFolderInfoModification;
@@ -189,14 +195,18 @@ public class FolderInfoModification extends ToolListModification implements IFol
 	}
 
 	public void setToolChain(IToolChain tc){
-		if(tc == fSelectedToolChain)
+		setToolChain(tc, false);
+	}
+
+	public void setToolChain(IToolChain tc, boolean force){
+		if(tc == fSelectedToolChain && !force)
 			return;
 	
 		applyToolChain((ToolChain)tc);
 
 		fSelectedToolChain = (ToolChain)tc;
 		IToolChain newReal = ManagedBuildManager.getRealToolChain(tc);
-		if(newReal == fRealToolChain)
+		if(newReal == fRealToolChain && !force)
 			return;
 
 		fRealToolChain = (ToolChain)newReal;
@@ -423,4 +433,41 @@ public class FolderInfoModification extends ToolListModification implements IFol
 			}
 		}
 	}
+
+	private IToolChain getDefaultToolChain(){
+		IResourceInfo rcInfo = getResourceInfo();
+		IToolChain defaultTc = null;
+		if (rcInfo.getPath().segmentCount() == 0) {
+//			1.Per-project : change to the "default" tool-chain defined in the extension
+//			super-class of the project configuration. NOTE: the makefile project case might
+//			need a special handling in this case.
+			
+			IConfiguration cfg = rcInfo.getParent();
+			IConfiguration extCfg = cfg.getParent();
+			defaultTc = extCfg.getToolChain(); 
+			if (defaultTc == null) {
+				if (cfg.getToolChain() != null) {
+					defaultTc = cfg.getToolChain().getSuperClass();
+				}
+			}
+		} else {
+//			2.per-folder : change to the same tool-chain as the one used by the parent
+//			folder.
+			IFolderInfo parentFo = ((ResourceInfo)rcInfo).getParentFolderInfo();
+			IToolChain tc = parentFo.getToolChain();
+			defaultTc = ManagedBuildManager.getExtensionToolChain(tc);
+		}
+		
+		if(defaultTc != null && defaultTc.getId().equals(ConfigurationDataProvider.PREF_TC_ID))
+			defaultTc = null;
+
+		return defaultTc;
+	}
+	
+	public final void restoreDefaults() {
+		IToolChain tc = getDefaultToolChain();
+		if(tc != null){
+			setToolChain(tc, true);
+		}
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/tcmodification/IToolListModification.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/tcmodification/IToolListModification.java
index 15dfcc7d4ef..460d5b33304 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/tcmodification/IToolListModification.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/tcmodification/IToolListModification.java
@@ -60,4 +60,6 @@ public interface IToolListModification extends IApplicableModification {
 	 * @return
 	 */
 	IToolModification getToolModification(ITool tool);
+	
+	void restoreDefaults();
 }