Initial check-in for the build environment variable support

38 files changed, 3553 insertions, 37 deletions

diff --git a/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd b/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
index 8cc0f1a7dcb..79f85f11548 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
+++ b/build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd
@@ -98,6 +98,16 @@
                </documentation>

             </annotation>

          </attribute>

+         <attribute name="projectEnvironmentSupplier" type="string">

+            <annotation>

+               <documentation>

+                  Specifies the name of the class that implements IProjectEnvironmentVariableSupplier

+               </documentation>

+               <appInfo>

+                  <meta.attribute kind="java" basedOn="org.eclipse.cdt.managedbuilder.envvar.IProjectEnvironmentVariableSupplier"/>

+               </appInfo>

+            </annotation>

+         </attribute>

       </complexType>

    </element>

 

@@ -318,6 +328,16 @@
                </appInfo>

             </annotation>

          </attribute>

+         <attribute name="configurationEnvironmentSupplier" type="string">

+            <annotation>

+               <documentation>

+                  Specifies the name of the class that implements IConfigurationEnvironmentVariableSupplier

+               </documentation>

+               <appInfo>

+                  <meta.attribute kind="java" basedOn="org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier"/>

+               </appInfo>

+            </annotation>

+         </attribute>

       </complexType>

    </element>

 

@@ -360,6 +380,7 @@
             <element ref="optionCategory"/>

             <element ref="inputType"/>

             <element ref="outputType"/>

+            <element ref="envVarBuildPath"/>

          </sequence>

          <attribute name="id" type="string" use="required">

             <annotation>

@@ -906,8 +927,8 @@
          <attribute name="valueType" use="default" value="string">

             <annotation>

                <documentation>

-                  General options can be one of the following types; &apos;string&apos; for catch-all entries for options that cannot be easily defined any other way, &apos;string list&apos; for entries that consist of a list of values such as defined symbols or paths, &apos;boolean&apos; for options that have two values, and &apos;enumerated&apos; for options that are one-of a list of values.
-
+                  General options can be one of the following types; &apos;string&apos; for catch-all entries for options that cannot be easily defined any other way, &apos;string list&apos; for entries that consist of a list of values such as defined symbols or paths, &apos;boolean&apos; for options that have two values, and &apos;enumerated&apos; for options that are one-of a list of values.

+

 Additional special types exist to flag options of special relevance to the build model; &apos;include&apos;, &apos;libs&apos;, &apos;userObjs&apos; and &apos;definedSymbols&apos;. You can pre-populate with optionValues, and they will display in the UI the same way the &apos;stringList&apos; options do. The build model will look specifically for these value types when clients query for include paths and preprocessor defines. The makefile generator will treat the libs and userObjs entries differently than other stringLists.

                </documentation>

             </annotation>

@@ -1231,14 +1252,14 @@ Additional special types exist to flag options of special relevance to the build
    <element name="managedBuildRevision">

       <annotation>

          <documentation>

-            &lt;p&gt;
-Version identifier for the managed build extension point. It is a string representation, consisting of three (3) tokens separated by a decimal point. The 3 tokens are positive integer numbers. For example, the following are valid version identifiers:
- &lt;ul&gt;
-  &lt;li&gt;&lt;code&gt;0.0.0&lt;/code&gt;&lt;/li&gt;
-  &lt;li&gt;&lt;code&gt;1.0.1234&lt;/code&gt;&lt;/li&gt;
-  &lt;li&gt;&lt;code&gt;1.9&lt;/code&gt; (interpreted as &lt;code&gt;1.9.0&lt;/code&gt;)&lt;/li&gt;
-  &lt;li&gt;&lt;code&gt;3&lt;/code&gt; (interpreted as &lt;code&gt;3.0.0&lt;/code&gt;)&lt;/li&gt;
- &lt;/ul&gt;
+            &lt;p&gt;

+Version identifier for the managed build extension point. It is a string representation, consisting of three (3) tokens separated by a decimal point. The 3 tokens are positive integer numbers. For example, the following are valid version identifiers:

+ &lt;ul&gt;

+  &lt;li&gt;&lt;code&gt;0.0.0&lt;/code&gt;&lt;/li&gt;

+  &lt;li&gt;&lt;code&gt;1.0.1234&lt;/code&gt;&lt;/li&gt;

+  &lt;li&gt;&lt;code&gt;1.9&lt;/code&gt; (interpreted as &lt;code&gt;1.9.0&lt;/code&gt;)&lt;/li&gt;

+  &lt;li&gt;&lt;code&gt;3&lt;/code&gt; (interpreted as &lt;code&gt;3.0.0&lt;/code&gt;)&lt;/li&gt;

+ &lt;/ul&gt;

 &lt;/p&gt;

          </documentation>

       </annotation>

@@ -1253,6 +1274,48 @@ Version identifier for the managed build extension point. It is a string represe
       </complexType>

    </element>

 

+   <element name="envVarBuildPath">

+      <annotation>

+         <documentation>

+            Defines a set of environment variables used by a tool to represent the build paths (include paths or library paths).

+         </documentation>

+      </annotation>

+      <complexType>

+         <attribute name="pathType" type="string" use="required">

+            <annotation>

+               <documentation>

+                  The build path type. Can be one of the following: &quot;buildpathInclude&quot;, &quot;buildpathLibrary&quot;

+               </documentation>

+            </annotation>

+         </attribute>

+         <attribute name="variableList" type="string" use="required">

+            <annotation>

+               <documentation>

+                  comma-separated list of the environment variable names used to store the include paths

+               </documentation>

+            </annotation>

+         </attribute>

+         <attribute name="pathDelimiter" type="string">

+            <annotation>

+               <documentation>

+                  Represent the delimiter used to separate the paths. If omitted the default system delimiter will be used. That is the &quot;:&quot; for Unix-like systems and the &quot;;&quot; for Win32 systems.

+If the &quot;buildPathResolver&quot; attribute is specified, the &quot;pathDelimiter&quot; is ignored

+               </documentation>

+            </annotation>

+         </attribute>

+         <attribute name="buildPathResolver" type="string">

+            <annotation>

+               <documentation>

+                  Should be set to the IBuildPathResolver interface that the tool-integrator can supply in order to provide his/her own logic of resolving the variable values to the build paths

+               </documentation>

+               <appInfo>

+                  <meta.attribute kind="java" basedOn="org.eclipse.cdt.managedbuilder.core.IBuildPathResolver"/>

+               </appInfo>

+            </annotation>

+         </attribute>

+      </complexType>

+   </element>

+

    <annotation>

       <appInfo>

          <meta.section type="since"/>

@@ -1267,14 +1330,14 @@ Version identifier for the managed build extension point. It is a string represe
          <meta.section type="examples"/>

       </appInfo>

       <documentation>

-         The following is an example of the extension point usage:
-&lt;p&gt;
-&lt;pre&gt;
-   &lt;extension
-         id=&quot;buildExample&quot;
-         name=&quot;Definitions for Build Example&quot;
-         point=&quot;org.eclipse.cdt.managedbuilder.core.buildDefinitions&quot;&gt;
-   etc...
+         The following is an example of the extension point usage:

+&lt;p&gt;

+&lt;pre&gt;

+   &lt;extension

+         id=&quot;buildExample&quot;

+         name=&quot;Definitions for Build Example&quot;

+         point=&quot;org.eclipse.cdt.managedbuilder.core.buildDefinitions&quot;&gt;

+   etc...

 &lt;/pre&gt;

       </documentation>

    </annotation>

@@ -1302,7 +1365,7 @@ Version identifier for the managed build extension point. It is a string represe
          <meta.section type="copyright"/>

       </appInfo>

       <documentation>

-         Copyright (c) 2003, 2005 IBM Corporation and others.
+         Copyright (c) 2003, 2005 IBM Corporation and others.

 All rights reserved. This program and the accompanying materials are made available under the terms of the Common Public License v1.0 which accompanies this distribution, and is available on the &lt;a href=&quot;http://www.eclipse.org/legal/cpl-v10.html&quot;&gt; Eclipse&lt;/a&gt; website.

       </documentation>

    </annotation>

diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IBuildPathResolver.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IBuildPathResolver.java
new file mode 100644
index 00000000000..45f4677df99
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IBuildPathResolver.java
@@ -0,0 +1,34 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.core;
+
+/**
+ * this interface is to be implemented by the tool-integrator to provide some specific
+ * logic for resolving the build path variable values to the build paths
+ * @since 3.0
+ */
+public interface IBuildPathResolver {
+
+	/**
+	 *
+	 * @param pathType one of the IEnvVarBuildPath.BUILDPATH _xxx
+	 * @param variableName represents the name of the variable that holds the build paths
+	 * @param variableValue represents the value of the value specified with the 
+	 *     variableName argument
+	 * @param configuration represents configuration for which the build paths are requested
+	 */
+	String[] resolveBuildPaths(
+			int pathType,
+			String variableName, 
+			String variableValue,
+			IConfiguration configuration);
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IConfiguration.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IConfiguration.java
index a11e0b82904..c369142d11f 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IConfiguration.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IConfiguration.java
@@ -10,6 +10,7 @@
  *******************************************************************************/
 package org.eclipse.cdt.managedbuilder.core;
 
+import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IResource;
 
@@ -425,4 +426,12 @@ public interface IConfiguration extends IBuildObject {
 	 * @return boolean 
 	 */	
 	public boolean isSupported();
+	
+	/**
+	 * Returns the implementation of the IConfigurationEnvironmentVariableSupplier provided
+	 * by the tool-integrator or <code>null</code> if none.
+	 * 
+	 * @return IConfigurationEnvironmentVariableSupplier 
+	 */	
+	public IConfigurationEnvironmentVariableSupplier getEnvironmentVariableSupplier();
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IEnvVarBuildPath.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IEnvVarBuildPath.java
new file mode 100644
index 00000000000..17b805aa449
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IEnvVarBuildPath.java
@@ -0,0 +1,61 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.core;
+
+/**
+ * 
+ * @since 3.0
+ */
+public interface IEnvVarBuildPath {
+	public static final int BUILDPATH_INCLUDE = 1;
+	public static final int BUILDPATH_LIBRARY = 2;
+
+	public static final String BUILD_PATH_ELEMENT_NAME = "envVarBuildPath";	//$NON-NLS-1$
+	public static final String TYPE = "pathType";	//$NON-NLS-1$
+	public static final String LIST = "variableList";	//$NON-NLS-1$
+	public static final String PATH_DELIMITER = "pathDelimiter";	//$NON-NLS-1$
+	public static final String BUILD_PATH_RESOLVER = "buildPathResolver";	//$NON-NLS-1$
+	
+	public static final String TYPE_INCLUDE = "buildpathInclude";	//$NON-NLS-1$
+	public static final String TYPE_LIBRARY = "buildpathLibrary";	//$NON-NLS-1$
+	
+	public static final String NAME_SEPARATOR = ",";	//$NON-NLS-1$
+	
+	/**
+	 *
+	 * @return one of the ITool.BUILDPATH _xxx
+	 */
+	public int getType();
+
+	/**
+	 *
+	 * @return the array of String representing the build variable names
+	 */
+	public String[] getVariableNames();
+
+	/**
+	 *
+	 * @return the String representing the path delimiter used in the variables returned by
+	 * the getVariableNames() method
+	 */
+	public String getPathDelimiter();
+
+	/**
+	 *
+	 * @return the IBuildPathResolver interface implementation provided by the tool-integrator
+	 * in order to specify his/her own logic of resolving the variable values to the build paths
+	 * (see also the "Specifying the Includes and Library paths environment variables" and
+	 * the "IBuildPathResolver" sections for more detail and for explanation why this callback
+	 * might be needed)
+	 */
+	public IBuildPathResolver getBuildPathResolver();
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IProjectType.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IProjectType.java
index 484992c42dd..c371372b4be 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IProjectType.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IProjectType.java
@@ -10,6 +10,9 @@
  **********************************************************************/
 package org.eclipse.cdt.managedbuilder.core;
 
+import org.eclipse.cdt.managedbuilder.envvar.IProjectEnvironmentVariableSupplier;
+import org.eclipse.core.runtime.IConfigurationElement;
+
 /**
  * This class represents project-types in the managed build system.
  * A project-type is a tool-integrator defined class of project which 
@@ -44,6 +47,7 @@ public interface IProjectType extends IBuildObject {
 	public static final String IS_ABSTRACT = "isAbstract";					//$NON-NLS-1$
 	public static final String UNUSED_CHILDREN = "unusedChildren";			//$NON-NLS-1$
 	public static final String IS_TEST = "isTest";							//$NON-NLS-1$
+	public static final String PROJECT_ENVIRONMENT_SUPPLIER = "projectEnvironmentSupplier";			//$NON-NLS-1$
 	
 	/**
 	 * Creates a configuration for this project-type populated with the tools
@@ -135,4 +139,12 @@ public interface IProjectType extends IBuildObject {
 	 * @return boolean 
 	 */	
 	public boolean isSupported();
+	
+	/**
+	 * Returns the tool-integrator provided implementation of the project environment variable supplier
+	 * or <code>null</code> if none. 
+	 *  
+	 * @return IProjectEnvironmentVariableSupplier
+	 */
+	public IProjectEnvironmentVariableSupplier getEnvironmentVariableSupplier();
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
index 13f09d5db74..58520462a54 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ITool.java
@@ -688,4 +688,11 @@ public interface ITool extends IBuildObject {
 	 * @return boolean 
 	 */
 	public boolean isExtensionElement();
+	
+	/**
+	 * Returns an array of the Environment Build Path variable descriptors
+	 * 
+	 * @return IEnvVarBuildPath[]
+	 */
+	public IEnvVarBuildPath[] getEnvVarBuildPaths();
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IToolChain.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IToolChain.java
index b2b19ada5a7..dd5f15f08f2 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IToolChain.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/IToolChain.java
@@ -10,6 +10,9 @@
  **********************************************************************/
 package org.eclipse.cdt.managedbuilder.core;
 
+import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
+import org.eclipse.core.runtime.IConfigurationElement;
+
 
 /**
  * This interface represents a tool-integrator-defined, ordered set of tools 
@@ -35,6 +38,8 @@ public interface IToolChain extends IBuildObject {
 	public static final String TARGET_TOOL = "targetTool";				//$NON-NLS-1$
 	public static final String SECONDARY_OUTPUTS = "secondaryOutputs";	//$NON-NLS-1$
 	public static final String IS_TOOL_CHAIN_SUPPORTED = "isToolChainSupported";			//$NON-NLS-1$
+	public static final String CONFIGURATION_ENVIRONMENT_SUPPLIER = "configurationEnvironmentSupplier";			//$NON-NLS-1$
+	
 	// The attribute name for the scanner info collector
 	public static final String SCANNER_CONFIG_PROFILE_ID = "scannerConfigDiscoveryProfileId"; //$NON-NLS-1$
 
@@ -289,4 +294,12 @@ public interface IToolChain extends IBuildObject {
 	 * @return boolean 
 	 */	
 	public boolean isSupported();
+	
+	/**
+	 * Returns the tool-integrator provided implementation of the configuration environment variable supplier
+	 * or <code>null</code> if none. 
+	 *  
+	 * @return IConfigurationEnvironmentVariableSupplier
+	 */
+	public IConfigurationEnvironmentVariableSupplier getEnvironmentVariableSupplier();
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
index fc5e97a4d69..29858ecef50 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/core/ManagedBuildManager.java
@@ -44,6 +44,8 @@ import org.eclipse.cdt.core.model.IPathEntry;
 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.managedbuilder.envvar.IEnvironmentBuildPathsChangeListener;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider;
 import org.eclipse.cdt.managedbuilder.internal.core.Builder;
 import org.eclipse.cdt.managedbuilder.internal.core.Configuration;
 import org.eclipse.cdt.managedbuilder.internal.core.DefaultManagedConfigElement;
@@ -61,6 +63,7 @@ import org.eclipse.cdt.managedbuilder.internal.core.Target;
 import org.eclipse.cdt.managedbuilder.internal.core.TargetPlatform;
 import org.eclipse.cdt.managedbuilder.internal.core.Tool;
 import org.eclipse.cdt.managedbuilder.internal.core.ToolChain;
+import org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider;
 import org.eclipse.cdt.managedbuilder.makegen.IManagedBuilderMakefileGenerator;
 import org.eclipse.cdt.managedbuilder.makegen.gnu.GnuMakefileGenerator;
 import org.eclipse.cdt.managedbuilder.projectconverter.UpdateManagedProjectManager;
@@ -155,7 +158,18 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 	private static Map buildModelListeners;
 	// Random number for derived object model elements
 	private static Random randomNumber;
+	// Environment Build Paths Change Listener
+	private static IEnvironmentBuildPathsChangeListener fEnvironmentBuildPathsChangeListener;
 	
+	static {
+		getEnvironmentVariableProvider().subscribe(
+				fEnvironmentBuildPathsChangeListener = new IEnvironmentBuildPathsChangeListener(){
+					public void buildPathsChanged(IConfiguration configuration, int buildPathType){
+						if(buildPathType == IEnvVarBuildPath.BUILDPATH_INCLUDE)
+							notifyListeners(configuration,null);
+					}
+				});
+	}
 	/**
 	 * Returns the next random number.
 	 * 
@@ -576,6 +590,7 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 	public static IManagedBuilderMakefileGenerator getBuildfileGenerator(IConfiguration config) {
 		try {
 			IToolChain toolChain = config.getToolChain();
+			if(toolChain != null){
 			IBuilder builder = toolChain.getBuilder();
 			IConfigurationElement element = builder.getBuildFileGeneratorElement();
 			if (element != null) {
@@ -590,6 +605,7 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 				}
 			}
 		} 
+		} 
 		catch (CoreException e) {
 			// Probably not defined
 		}
@@ -650,7 +666,9 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 	private static void notifyListeners(IConfiguration config, IOption option) {
 		// Continue if change is something that effect the scanner
 		try {
-			if (!(option.getValueType() == IOption.INCLUDE_PATH 
+			//an option can be null in the case of calling this method from the environment
+			//build path change listener
+			if (option != null && !(option.getValueType() == IOption.INCLUDE_PATH 
 				|| option.getValueType() == IOption.PREPROCESSOR_SYMBOLS)) {
 				return;
 			}
@@ -1330,7 +1348,7 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 					buildInfo.setVersion(fileVersion);
 				}
 				if(!UpdateManagedProjectManager.isCompatibleProject(buildInfo)){
-					UpdateManagedProjectManager.updateProject(project, buildInfo);
+						UpdateManagedProjectManager.updateProject(project,buildInfo);
 				}
 				if (buildInfo.getManagedProject() == null ||
 					(!buildInfo.getManagedProject().isValid())) {
@@ -2024,4 +2042,13 @@ public class ManagedBuildManager extends AbstractCExtension implements IScannerI
 	public static void OutputManifestError(String message) {
 		System.err.println(ManagedMakeMessages.getResourceString(MANIFEST_ERROR_HEADER) + message + NEWLINE);
 	}
+	
+	/**
+	 * Returns the instance of the Environment Variable Provider
+	 * 
+	 * @return IEnvironmentVariableProvider
+	 */
+	public static IEnvironmentVariableProvider getEnvironmentVariableProvider(){
+		return EnvironmentVariableProvider.getDefault();
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IBuildEnvironmentVariable.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IBuildEnvironmentVariable.java
new file mode 100644
index 00000000000..8086a64e315
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IBuildEnvironmentVariable.java
@@ -0,0 +1,69 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+/**
+ * this interface represents the given environment variable 
+ * @since 3.0
+ */
+public interface IBuildEnvironmentVariable{
+	public static final int ENVVAR_REPLACE = 1;
+	public static final int ENVVAR_REMOVE = 2;
+	public static final int ENVVAR_PREPEND = 3;
+	public static final int ENVVAR_APPEND = 4;
+
+	/**
+	 * 
+	 * @return the variable name
+	 */
+	public String getName();
+
+	/**
+	 * 
+	 * @return the variable value
+	 */
+	public String getValue();
+
+	/**
+	 * @return one of the IBuildEnvironmentVariable.ENVVAR_* operation types
+	 */
+	public int getOperation();
+
+	/**
+	 * @return if the variable can hold the list of values this method returns the String representing
+	 * the delimiter that is used to separate values. This information is used for the following:
+	 *
+	 * 1. in append and prepend operations:
+	 * If the variable already exists and contains some value the new 
+	 * value will be calculated in the following way:
+	 * For the "prepend" operation:
+	 * 	<New value> = <the value from the getValue() method><delimiter><Old value>
+	 * For the "append" operation:
+	 * 	<New value> = <Old value><delimiter><the value from the getValue() method>
+	 * 
+	 * The Environment Variable Provider will also remove the duplicates of "sub-values" 
+	 * in the resulting value. 
+	 * For example:
+	 * If the current value is "string1:string2:string3", the getDelimiter() method returns “:” 
+	 * and getValue() method returns "string4:string2" the new value will contain:
+	 * For the "prepend" operation: "string4:string2:string1:string3"
+	 * For the "append" operation: "string1:string3:string4:string2"
+	 * 
+	 * 2. Since the environment variables are also treated as build macros the delimiter is also used 
+	 * by the BuildMacroProvider to determine the type of the macro used to represent the
+	 * given environment variable. If the variable has the delimiter it is treated as the Text-List macro
+	 * otherwise it is treated as the Text macro. (See Build Macro design for more details)
+	 * 
+	 * To specify that no delimiter should be used, the getDelimiter() method should
+	 * return null or an empty string
+ 	 */
+	public String getDelimiter();
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IConfigurationEnvironmentVariableSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IConfigurationEnvironmentVariableSupplier.java
new file mode 100644
index 00000000000..9fd80574782
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IConfigurationEnvironmentVariableSupplier.java
@@ -0,0 +1,61 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+
+/**
+ * 
+ * this interface is to be implemented by the tool-integrator
+ * for supplying the configuration-specific environment
+ * 
+ * @since 3.0
+ */
+public interface IConfigurationEnvironmentVariableSupplier{
+	/**
+	 *
+	 * @param variableName the variable mane
+	 * @param configuration configuration
+	 * @param provider the instance of the environment variable provider to be used for querying the
+	 * environment variables from within the supplier. The supplier should use this provider to obtain
+	 * the already defined environment instead of using the "default" provider returned by the
+	 * ManagedBuildManager.getEnvironmentVariableProvider().
+	 * The provider passed to a supplier will ignore searching the variables for the levels 
+	 * higher than the current supplier level, will query only the lower-precedence suppliers 
+	 * for the current level and will query all suppliers for the lower levels. 
+	 * This is done to avoid infinite loops that could be caused if the supplier calls the provider 
+	 * and the provider in turn calls that supplier again. Also the supplier should not know anything
+	 * about the environment variables defined for the higher levels.
+	 * @return the reference to the IBuildEnvironmentVariable interface representing 
+	 * the variable of a given name
+	 */
+	IBuildEnvironmentVariable getVariable(String variableName, 
+			IConfiguration configuration,
+			IEnvironmentVariableProvider provider);
+
+	/**
+	 * @param configuration configuration
+	 * @param provider the instance of the environment variable provider to be used for querying the
+	 * environment variables from within the supplier. The supplier should use this provider to obtain
+	 * the already defined environment instead of using the "default" provider returned by the
+	 * ManagedBuildManager.getEnvironmentVariableProvider().
+	 * The provider passed to a supplier will ignore searching the variables for the levels 
+	 * higher than the current supplier level, will query only the lower-precedence suppliers 
+	 * for the current level and will query all suppliers for the lower levels. 
+	 * This is done to avoid infinite loops that could be caused if the supplier calls the provider 
+	 * and the provider in turn calls that supplier again. Also the supplier should not know anything
+	 * about the environment variables defined for the higher levels.
+	 * @return the array of IBuildEnvironmentVariable that represents the environment variables
+	 */
+	IBuildEnvironmentVariable[] getVariables (IConfiguration configuration,
+			IEnvironmentVariableProvider provider);
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentBuildPathsChangeListener.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentBuildPathsChangeListener.java
new file mode 100644
index 00000000000..006f1b82f32
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentBuildPathsChangeListener.java
@@ -0,0 +1,34 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+
+/**
+ * 
+ * listeners of the environment build path changes should implement this interface
+ * 
+ * @since 3.0
+ */
+public interface IEnvironmentBuildPathsChangeListener {
+
+	/**
+	 *
+	 * @param configuration represent the configuration for which the paths were changed
+	 * @param buildPathType set to one of 
+	 * the IEnvVarBuildPath.BUILDPATH_xxx 
+	 * (the IEnvVarBuildPath will represent the build environment variables, see also 
+	 * the "Specifying the Includes and Library paths environment variables",
+	 * the "envVarBuildPath schema" and the "Expected CDT/MBS code changes" sections)
+	 */
+	void buildPathsChanged(IConfiguration configuration, int buildPathType);
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableProvider.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableProvider.java
new file mode 100644
index 00000000000..ea55e0be1af
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableProvider.java
@@ -0,0 +1,112 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+
+/**
+ * 
+ * this interface represent the environment variable provider - the main entry-point
+ * to be used for querying the build environment
+ * 
+ * @since 3.0
+ */
+public interface IEnvironmentVariableProvider{
+
+	/**
+	 * 
+	 * 
+	 * @return the reference to the IBuildEnvironmentVariable interface representing 
+	 * the variable of a given name
+	 * @param variableName environment variable name
+	 * if environment variable names are case insensitive in the current OS, 
+	 * the environment variable provider will query the getVariable method of suppliers always
+	 * passing it the uppercase variable name not depending on the case of the variableName
+	 * passed to the IEnvironmentVariableProvider.getVariable() method. This will prevent the 
+	 * supplier from answering different values for the same variable given the names that differ
+	 * only by case. E.g. if the current OS does not support case sensitive variables both of the 
+	 * calls below:
+	 *
+	 *   provider.getVariable("FOO",level,includeParentContexts);
+	 *   provider.getVariable("foo",level,includeParentContexts);
+	 *
+	 * will result in asking suppliers for the "FOO" variable
+	 *
+	 * @param level could be one of the following:
+	 *    1. IConfiguration to represent the configuration
+	 *    2. IManagedProject to represent the managed project
+	 *    3. IWorkspace to represent the workspace
+	 *    4. null to represent the system environment passed to eclipse
+	 */
+	public IBuildEnvironmentVariable getVariable(
+				String variableName, Object level, boolean includeParentLevels);
+
+	/**
+	 *
+	 * if environment variable names are case insensitive in the current OS, 
+	 * the environment variable provider will remove the duplicates of the variables if their names
+	 * differ only by case
+	 *
+	 * @return the array of IBuildEnvironmentVariable that represents the environment variables 
+	 */
+	public IBuildEnvironmentVariable[] getVariables(
+				Object level, boolean includeParentLevels);
+
+	/**
+	 *
+	 * @return the String representing default system delimiter. That is the ":" for Unix-like
+	 * systems and the ";" for Win32 systems. This method will be used by the 
+	 * tool-integrator provided variable supplier e.g. in order to concatenate the list of paths into the 
+	 * environment variable, etc.
+	 */
+	public String getDefaultDelimiter();
+
+	/**
+	 * @return true if the OS supports case sensitive variables (Unix-like systems) or false 
+	 * if it does not (Win32 systems)
+	 */
+	public boolean isVariableCaseSensitive();
+
+	/**
+	 * This method is defined to be used basically by the UI classes and should not be used by the
+	 * tool-integrator
+	 * @return the array of the provider-internal suppliers for the given level
+	 */
+	IEnvironmentVariableSupplier[] getSuppliers(Object level);
+
+
+	/**
+	 * returns the array of String that holds the build paths of the specified type
+	 * @param configuration represent the configuration for which the paths were changed
+	 * @param buildPathType can be set to one of the IEnvVarBuildPath.BUILDPATH _xxx 
+	 * (the IEnvVarBuildPath will represent the build environment variables, see also 
+	 * the "Specifying the Includes and Library paths environment variables",
+	 * the "envVarBuildPath schema" and the "Expected CDT/MBS code changes" sections)
+	 */
+	String[] getBuildPaths(IConfiguration configuration, int buildPathType);
+
+	/**
+	 *
+	 * adds the listener that will return notifications about the include and library paths changes. 
+	 * The ManagedBuildManager will register the change listener and will notify all registered
+	 * Scanned Info Change Listeners about the include paths change. 
+	 */ 
+	void subscribe(
+		IEnvironmentBuildPathsChangeListener listener);
+
+	/**
+	 *
+	 * removes the include and library paths change listener 
+	 */ 
+	void unsubscribe(
+		IEnvironmentBuildPathsChangeListener listener);
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableSupplier.java
new file mode 100644
index 00000000000..257ad01bf97
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IEnvironmentVariableSupplier.java
@@ -0,0 +1,34 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+/**
+ * 
+ * @since 3.0
+ */
+public interface IEnvironmentVariableSupplier {
+	
+	/**
+	 *
+	 * @param name the variable mane
+	 * @param context the context
+	 * @return the reference to the IBuildEnvironmentVariable interface representing 
+	 * the variable of a given name
+	 */
+	IBuildEnvironmentVariable getVariable(String name, Object context);
+	
+	/**
+	 *
+	 * @param context the context
+	 * @return the array of IBuildEnvironmentVariable that represents the environment variables 
+	 */
+	IBuildEnvironmentVariable[] getVariables(Object context);
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IProjectEnvironmentVariableSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IProjectEnvironmentVariableSupplier.java
new file mode 100644
index 00000000000..fb1b3cc789c
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/envvar/IProjectEnvironmentVariableSupplier.java
@@ -0,0 +1,62 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IManagedProject;
+
+/**
+ * 
+ * this interface is to be implemented by the tool-integrator
+ * for supplying the project-specific environment
+ * 
+ * @since 3.0
+ */
+public interface IProjectEnvironmentVariableSupplier{
+	/**
+	 *
+	 * @param variableName the variable mane
+	 * @param project the managed project
+	 * @param provider the instance of the environment variable provider to be used for querying the
+	 * environment variables from within the supplier. The supplier should use this provider to obtain
+	 * the already defined environment instead of using the "default" provider returned by the
+	 * ManagedBuildManager.getEnvironmentVariableProvider().
+	 * The provider passed to a supplier will ignore searching the variables for the levels 
+	 * higher than the current supplier level, will query only the lower-precedence suppliers 
+	 * for the current level and will query all suppliers for the lower levels. 
+	 * This is done to avoid infinite loops that could be caused if the supplier calls the provider 
+	 * and the provider in turn calls that supplier again. Also the supplier should not know anything
+	 * about the environment variables defined for the higher levels.
+	 * @return the reference to the IBuildEnvironmentVariable interface representing 
+	 * the variable of a given name
+	 */
+	IBuildEnvironmentVariable getVariable(String variableName, 
+			IManagedProject project,
+			IEnvironmentVariableProvider provider);
+
+	/**
+	 *
+	 * @param project the managed project
+	 * @param provider the instance of the environment variable provider to be used for querying the
+	 * environment variables from within the supplier. The supplier should use this provider to obtain
+	 * the already defined environment instead of using the "default" provider returned by the
+	 * ManagedBuildManager.getEnvironmentVariableProvider().
+	 * The provider passed to a supplier will ignore searching the variables for the levels 
+	 * higher than the current supplier level, will query only the lower-precedence suppliers 
+	 * for the current level and will query all suppliers for the lower levels. 
+	 * This is done to avoid infinite loops that could be caused if the supplier calls the provider 
+	 * and the provider in turn calls that supplier again. Also the supplier should not know anything
+	 * about the environment variables defined for the higher levels.
+	 * @return the array of IBuildEnvironmentVariable that represents the environment variables 
+	 */
+	IBuildEnvironmentVariable[] getVariables (IManagedProject project,
+			IEnvironmentVariableProvider provider);
+}
+
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Configuration.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Configuration.java
index bb86377bbcc..2109111bc1b 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Configuration.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Configuration.java
@@ -34,6 +34,8 @@ import org.eclipse.cdt.managedbuilder.core.IBuilder;
 import org.eclipse.cdt.managedbuilder.core.IResourceConfiguration;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
 import org.eclipse.cdt.managedbuilder.internal.core.ResourceConfiguration;
+import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
+import org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider;
 import org.eclipse.core.resources.IFile;
 import org.eclipse.core.resources.IProject;
 import org.eclipse.core.resources.IResource;
@@ -1208,6 +1210,8 @@ public class Configuration extends BuildObject implements IConfiguration {
 	 */
 	public void setRebuildState(boolean rebuild) {
 		rebuildNeeded = rebuild;
+		if(rebuild)
+			((EnvironmentVariableProvider)ManagedBuildManager.getEnvironmentVariableProvider()).checkBuildPathVariables(this);
 	}
 
 	/* (non-Javadoc)
@@ -1297,4 +1301,14 @@ public class Configuration extends BuildObject implements IConfiguration {
 		addResourceConfiguration(resConfig);
 		return resConfig;
 	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IConfiguration#getEnvironmentVariableSupplier()
+	 */
+	public IConfigurationEnvironmentVariableSupplier getEnvironmentVariableSupplier(){
+		IToolChain toolChain = getToolChain();
+		if(toolChain != null)
+			return toolChain.getEnvironmentVariableSupplier();
+		return null;
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/EnvVarBuildPath.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/EnvVarBuildPath.java
new file mode 100644
index 00000000000..5b091ddca32
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/EnvVarBuildPath.java
@@ -0,0 +1,138 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.core;
+
+import org.eclipse.cdt.managedbuilder.core.IBuildPathResolver;
+import org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath;
+import org.eclipse.cdt.managedbuilder.core.IManagedConfigElement;
+import org.eclipse.cdt.managedbuilder.core.ITool;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IConfigurationElement;
+
+public class EnvVarBuildPath implements
+		IEnvVarBuildPath {
+	private ITool tool;
+	
+	private int type;
+	private String variableNames[];
+	private String pathDelimiter;
+	private IBuildPathResolver buildPathResolver;
+	private IConfigurationElement buildPathResolverElement;
+
+
+	/**
+	 * Constructor to create an EnvVarBuildPath based on an element from the plugin
+	 * manifest. 
+	 * 
+	 * @param element The element containing the information about the tool.
+	 */
+	public EnvVarBuildPath(ITool tool, IManagedConfigElement element) {
+		this.tool = tool;
+		loadFromManifest(element);
+	}
+	
+	/* (non-Javadoc)
+	 * Load the EnvVarBuildPath information from the XML element specified in the 
+	 * argument
+	 * @param element An XML element containing the tool information 
+	 */
+	protected void loadFromManifest(IManagedConfigElement element) {
+		
+		setType(convertPathTypeToInt(element.getAttribute(TYPE)));
+		
+		setVariableNames(element.getAttribute(LIST));
+		
+		setPathDelimiter(element.getAttribute(PATH_DELIMITER));
+		
+		// Store the configuration element IFF there is a build path resolver defined 
+		String buildPathResolver = element.getAttribute(BUILD_PATH_RESOLVER); 
+		if (buildPathResolver != null && element instanceof DefaultManagedConfigElement) {
+			buildPathResolverElement = ((DefaultManagedConfigElement)element).getConfigurationElement();			
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath#getType()
+	 */
+	public int getType() {
+		return type;
+	}
+	
+	public void setType(int type){
+		this.type = type;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath#getVariableNames()
+	 */
+	public String[] getVariableNames() {
+		return variableNames;
+	}
+	
+	public void setVariableNames(String names[]){
+		this.variableNames = names;
+	}
+
+	public void setVariableNames(String names){
+		setVariableNames(getNamesFromString(names));
+	}
+	
+	public String[] getNamesFromString(String names){
+		if(names == null)
+			return null;
+		return names.split(NAME_SEPARATOR);
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath#getPathDelimiter()
+	 */
+	public String getPathDelimiter() {
+		return pathDelimiter;
+	}
+
+	public void setPathDelimiter(String delimiter) {
+		if(delimiter == null)
+			delimiter = ManagedBuildManager.getEnvironmentVariableProvider().getDefaultDelimiter();
+		this.pathDelimiter = delimiter;
+	}
+
+	private int convertPathTypeToInt(String pathType){
+		if(pathType != null && TYPE_LIBRARY.equals(pathType))
+			return BUILDPATH_LIBRARY;
+		return BUILDPATH_INCLUDE;
+	}
+
+	private String convertPathTypeToString(int pathType){
+		switch(pathType){
+		case BUILDPATH_LIBRARY:
+			return TYPE_LIBRARY;
+		case BUILDPATH_INCLUDE:
+		default:
+			return TYPE_INCLUDE;
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath#getBuildPathResolver()
+	 */
+	public IBuildPathResolver getBuildPathResolver() {
+		if(buildPathResolver == null && buildPathResolverElement != null){
+			try {
+				if (buildPathResolverElement.getAttribute(BUILD_PATH_RESOLVER) != null) {
+					buildPathResolver = (IBuildPathResolver) buildPathResolverElement.createExecutableExtension(BUILD_PATH_RESOLVER);
+				}
+			} catch (CoreException e) {}
+		}
+		return buildPathResolver;
+	}
+
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/GeneratedMakefileBuilder.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/GeneratedMakefileBuilder.java
index 1198912dd7a..986d6ef6ae6 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/GeneratedMakefileBuilder.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/GeneratedMakefileBuilder.java
@@ -1,5 +1,5 @@
 /**********************************************************************
- * Copyright (c) 2002, 2005 IBM Corporation and others.
+ * Copyright (c) 2002,2005 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Common Public License v0.5
  * which accompanies this distribution, and is available at
@@ -32,6 +32,7 @@ import org.eclipse.cdt.core.resources.IConsole;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration; 
 import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
 import org.eclipse.cdt.managedbuilder.makegen.IManagedBuilderMakefileGenerator;
 import org.eclipse.core.resources.IContainer;
 import org.eclipse.core.resources.IFile;
@@ -608,17 +609,13 @@ public class GeneratedMakefileBuilder extends ACBuilder {
 				CommandLauncher launcher = new CommandLauncher();
 				launcher.showCommand(true);
 	
-				// Set the environmennt, some scripts may need the CWD var to be set.
-				Properties props = launcher.getEnvironment();
-				props.put("CWD", workingDirectory.toOSString());	//$NON-NLS-1$
-				props.put("PWD", workingDirectory.toOSString());	//$NON-NLS-1$
+				// Set the environmennt
+				IBuildEnvironmentVariable variables[] = ManagedBuildManager.getEnvironmentVariableProvider().getVariables(cfg,true);
 				String[] env = null;
 				ArrayList envList = new ArrayList();
-				Enumeration names = props.propertyNames();
-				if (names != null) {
-					while (names.hasMoreElements()) {
-						String key = (String) names.nextElement();
-						envList.add(key + "=" + props.getProperty(key)); //$NON-NLS-1$
+				if (variables != null) {
+					for(int i = 0; i < variables.length; i++){
+						envList.add(variables[i].getName() + "=" + variables[i].getValue());	//$NON-NLS-1$
 					}
 					env = (String[]) envList.toArray(new String[envList.size()]);
 				}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ManagedBuildInfo.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ManagedBuildInfo.java
index 3146ee3a142..ff2ad71f0ef 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ManagedBuildInfo.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ManagedBuildInfo.java
@@ -1,5 +1,5 @@
 /**********************************************************************
- * Copyright (c) 2002, 2005 IBM Software Corporation and others.
+ * Copyright (c) 2002,2005 IBM Software Corporation and others.
  * All rights reserved.   This program and the accompanying materials
  * are made available under the terms of the Common Public License v0.5
  * which accompanies this distribution, and is available at
@@ -30,16 +30,18 @@ import org.eclipse.cdt.core.model.IPathEntry;
 import org.eclipse.cdt.core.model.IPathEntryContainer;
 import org.eclipse.cdt.core.parser.IScannerInfo;
 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.IEnvVarBuildPath;
 import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
 import org.eclipse.cdt.managedbuilder.core.IManagedCommandLineGenerator;
 import org.eclipse.cdt.managedbuilder.core.IManagedCommandLineInfo;
 import org.eclipse.cdt.managedbuilder.core.IManagedProject;
+import org.eclipse.cdt.managedbuilder.core.IOption;
 import org.eclipse.cdt.managedbuilder.core.ITarget;
-import org.eclipse.cdt.managedbuilder.core.IConfiguration;
-import org.eclipse.cdt.managedbuilder.core.IToolChain;
 import org.eclipse.cdt.managedbuilder.core.ITool;
-import org.eclipse.cdt.managedbuilder.core.IOption;
-import org.eclipse.cdt.managedbuilder.core.IBuilder;
+import org.eclipse.cdt.managedbuilder.core.IToolChain;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuilderCorePlugin;
 import org.eclipse.cdt.managedbuilder.internal.scannerconfig.ManagedBuildCPathEntryContainer;
 import org.eclipse.cdt.managedbuilder.makegen.IManagedDependencyGenerator;
@@ -440,6 +442,11 @@ public class ManagedBuildInfo implements IManagedBuildInfo, IScannerInfo {
 			}
 		}
 		
+		//add paths specified in the environment
+		String envIncludePaths[] = ManagedBuildManager.getEnvironmentVariableProvider().getBuildPaths(config,IEnvVarBuildPath.BUILDPATH_INCLUDE);
+		if(envIncludePaths != null)
+			paths.addAll(Arrays.asList(envIncludePaths));
+		
 		// Answer the results as an array
 		return (String[])paths.toArray(new String[paths.size()]); 
 	}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/PluginResources.properties b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/PluginResources.properties
index 08ade51f11f..762c99fe167 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/PluginResources.properties
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/PluginResources.properties
@@ -79,4 +79,6 @@ ManagedBuildInfo.message.init.ok = Initializing path container succeeded for {0}
 GnuMakefileGenerator.message.postproc.dep.file=Verifying contents of dependency file {0}
 
 # Tool strings
-Tool.default.announcement=Invoking:
\ No newline at end of file
+Tool.default.announcement=Invoking:
+#Environment loader messages
+StorableEnvironmentLoader.storeOutputStream.wrong.arguments="Wrong arguments"
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ProjectType.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ProjectType.java
index 0fcbbe7b836..524682c2de2 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ProjectType.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ProjectType.java
@@ -20,6 +20,9 @@ import org.eclipse.cdt.managedbuilder.core.IProjectType;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
 import org.eclipse.cdt.managedbuilder.core.IManagedConfigElement;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IProjectEnvironmentVariableSupplier;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IConfigurationElement;
 
 public class ProjectType extends BuildObject implements IProjectType {
 	
@@ -36,6 +39,9 @@ public class ProjectType extends BuildObject implements IProjectType {
 	private Boolean isAbstract;
 	private Boolean isTest;
 	private String unusedChildren;
+	private IConfigurationElement environmentVariableSupplierElement = null;
+	private IProjectEnvironmentVariableSupplier environmentVariableSupplier = null;
+
 	//  Miscellaneous
 	private boolean resolved = true;
 
@@ -122,6 +128,13 @@ public class ProjectType extends BuildObject implements IProjectType {
         if (isTestStr != null){
     		isTest = new Boolean("true".equals(isTestStr)); //$NON-NLS-1$
         }
+		
+		// Get the environmentVariableSupplier configuration element
+		String environmentVariableSupplier = element.getAttribute(PROJECT_ENVIRONMENT_SUPPLIER); 
+		if(environmentVariableSupplier != null && element instanceof DefaultManagedConfigElement){
+			environmentVariableSupplierElement = ((DefaultManagedConfigElement)element).getConfigurationElement();
+		}
+
 	}
 
 	/*
@@ -350,4 +363,38 @@ public class ProjectType extends BuildObject implements IProjectType {
 		}
 		return false;
 	}
+	
+	/**
+	 * Returns the plugin.xml element of the projectEnvironmentSupplier extension or <code>null</code> if none. 
+	 *  
+	 * @return IConfigurationElement
+	 */
+	public IConfigurationElement getEnvironmentVariableSupplierElement(){
+		if (environmentVariableSupplierElement == null) {
+			if (superClass != null && superClass instanceof ProjectType) {
+				return ((ProjectType)superClass).getEnvironmentVariableSupplierElement();
+			}
+		}
+		return environmentVariableSupplierElement;
+	}
+
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.core.build.managed.IProjectType#getEnvironmentVariableSupplier()
+	 */
+	public IProjectEnvironmentVariableSupplier getEnvironmentVariableSupplier(){
+		if (environmentVariableSupplier != null) {
+			return environmentVariableSupplier;
+		}
+		IConfigurationElement element = getEnvironmentVariableSupplierElement();
+		if (element != null) {
+			try {
+				if (element.getAttribute(PROJECT_ENVIRONMENT_SUPPLIER) != null) {
+					environmentVariableSupplier = (IProjectEnvironmentVariableSupplier) element.createExecutableExtension(PROJECT_ENVIRONMENT_SUPPLIER);
+					return environmentVariableSupplier;
+				}
+			} catch (CoreException e) {}
+		}
+		return null;
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
index 0ec1a4ea069..b7927952533 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/Tool.java
@@ -21,6 +21,7 @@ import java.util.Vector;
 import org.eclipse.cdt.managedbuilder.core.BuildException;
 import org.eclipse.cdt.managedbuilder.core.IBuildObject;
 import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath;
 import org.eclipse.cdt.managedbuilder.core.IManagedConfigElement;
 import org.eclipse.cdt.managedbuilder.core.IOption;
 import org.eclipse.cdt.managedbuilder.core.IOptionCategory;
@@ -73,6 +74,7 @@ public class Tool extends BuildObject implements ITool, IOptionCategory {
 	private Map inputTypeMap;
 	private Vector outputTypeList;
 	private Map outputTypeMap;
+	private List envVarBuildPathList;
 	//  Managed Build model attributes
 	private String unusedChildren;
 	private Boolean isAbstract;
@@ -136,6 +138,8 @@ public class Tool extends BuildObject implements ITool, IOptionCategory {
 			} else if (toolElement.getName().equals(ITool.OUTPUT_TYPE)) {
 				OutputType outputType = new OutputType(this, toolElement);
 				addOutputType(outputType);
+			} else if (toolElement.getName().equals(IEnvVarBuildPath.BUILD_PATH_ELEMENT_NAME)){
+				addEnvVarBuildPath(new EnvVarBuildPath(this,toolElement));
 			}
 		}
 	}
@@ -310,6 +314,9 @@ public class Tool extends BuildObject implements ITool, IOptionCategory {
 		dependencyGeneratorElement = tool.dependencyGeneratorElement; 
 		dependencyGenerator = tool.dependencyGenerator; 
 
+		if(tool.envVarBuildPathList != null)
+			envVarBuildPathList = new ArrayList(tool.envVarBuildPathList);
+		
 		//  Clone the children
 		//  Note: This constructor ignores OptionCategories since they should not be
 		//        found on an non-extension tool - TODO: This may need to change!
@@ -2316,4 +2323,27 @@ public class Tool extends BuildObject implements ITool, IOptionCategory {
 	    }
 	}
 
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.ITool#getEnvVarBuildPaths()
+	 */
+	public IEnvVarBuildPath[] getEnvVarBuildPaths(){
+		if(envVarBuildPathList != null){
+			return (IEnvVarBuildPath[])envVarBuildPathList.toArray(
+					new IEnvVarBuildPath[envVarBuildPathList.size()]);
+		}
+		else if(superClass != null)
+			return superClass.getEnvVarBuildPaths();
+		return null;
+	}
+	
+	private void addEnvVarBuildPath(IEnvVarBuildPath path){
+		if(path == null)
+			return;
+		if(envVarBuildPathList == null)
+			envVarBuildPathList = new ArrayList();
+			
+		envVarBuildPathList.add(path);
+	}
+	
+	
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolChain.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolChain.java
index cbed05ea471..376f8dd2b8c 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolChain.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolChain.java
@@ -28,6 +28,7 @@ import org.eclipse.cdt.managedbuilder.core.ITargetPlatform;
 import org.eclipse.cdt.managedbuilder.core.ITool;
 import org.eclipse.cdt.managedbuilder.core.IToolChain;
 import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
 import org.eclipse.core.runtime.CoreException;
 import org.eclipse.core.runtime.IConfigurationElement;
 import org.w3c.dom.Document;
@@ -59,6 +60,9 @@ public class ToolChain extends BuildObject implements IToolChain {
     private String scannerConfigDiscoveryProfileId;
 	private IConfigurationElement managedIsToolChainSupportedElement = null;
 	private IManagedIsToolChainSupported managedIsToolChainSupported = null;
+	private IConfigurationElement environmentVariableSupplierElement = null;
+	private IConfigurationEnvironmentVariableSupplier environmentVariableSupplier = null;
+
 	//  Miscellaneous
 	private boolean isExtensionToolChain = false;
 	private boolean isDirty = false;
@@ -225,6 +229,9 @@ public class ToolChain extends BuildObject implements IToolChain {
 		managedIsToolChainSupportedElement = toolChain.managedIsToolChainSupportedElement; 
 		managedIsToolChainSupported = toolChain.managedIsToolChainSupported; 
 
+		environmentVariableSupplierElement = toolChain.environmentVariableSupplierElement;
+		environmentVariableSupplier = toolChain.environmentVariableSupplier;
+
 		//  Clone the children
 		if (toolChain.builder != null) {
 			int nnn = ManagedBuildManager.getRandomNumber();
@@ -342,6 +349,12 @@ public class ToolChain extends BuildObject implements IToolChain {
 		if (managedIsToolChainSupported != null && element instanceof DefaultManagedConfigElement) {
 			managedIsToolChainSupportedElement = ((DefaultManagedConfigElement)element).getConfigurationElement();			
 		} 
+		
+		// Get the environmentVariableSupplier configuration element
+		String environmentVariableSupplier = element.getAttribute(CONFIGURATION_ENVIRONMENT_SUPPLIER); 
+		if(environmentVariableSupplier != null && element instanceof DefaultManagedConfigElement){
+			environmentVariableSupplierElement = ((DefaultManagedConfigElement)element).getConfigurationElement();
+		}
 	}
 	
 	/* (non-Javadoc)
@@ -519,6 +532,12 @@ public class ToolChain extends BuildObject implements IToolChain {
 			//  TODO:  issue warning?
 		}
 
+		// Note: environmentVariableSupplier cannot be specified in a project file because
+		//       an IConfigurationElement is needed to load it!
+		if(environmentVariableSupplierElement != null) {
+			//  TODO:  issue warning?
+		}
+
 		// I am clean now
 		isDirty = false;
 	}
@@ -1124,4 +1143,38 @@ public class ToolChain extends BuildObject implements IToolChain {
 			return true;
 	}
 
+	/**
+	 * Returns the plugin.xml element of the configurationEnvironmentSupplier extension or <code>null</code> if none. 
+	 *  
+	 * @return IConfigurationElement
+	 */
+	public IConfigurationElement getEnvironmentVariableSupplierElement(){
+		if (environmentVariableSupplierElement == null) {
+			if (superClass != null && superClass instanceof ToolChain) {
+				return ((ToolChain)superClass).getEnvironmentVariableSupplierElement();
+			}
+		}
+		return environmentVariableSupplierElement;
+	}
+
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.core.IToolChain#getEnvironmentVariableSupplier()
+	 */
+	public IConfigurationEnvironmentVariableSupplier getEnvironmentVariableSupplier(){
+		if (environmentVariableSupplier != null) {
+			return environmentVariableSupplier;
+		}
+		IConfigurationElement element = getEnvironmentVariableSupplierElement();
+		if (element != null) {
+			try {
+				if (element.getAttribute(CONFIGURATION_ENVIRONMENT_SUPPLIER) != null) {
+					environmentVariableSupplier = (IConfigurationEnvironmentVariableSupplier) element.createExecutableExtension(CONFIGURATION_ENVIRONMENT_SUPPLIER);
+					return environmentVariableSupplier;
+				}
+			} catch (CoreException e) {}
+		}
+		return null;
+	}
+
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolReference.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolReference.java
index c879ac39dac..b91797429bf 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolReference.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/core/ToolReference.java
@@ -19,6 +19,7 @@ import org.eclipse.cdt.managedbuilder.core.BuildException;
 import org.eclipse.cdt.managedbuilder.core.IBuildObject;
 import org.eclipse.cdt.managedbuilder.core.IConfigurationV2;
 import org.eclipse.cdt.managedbuilder.core.IInputType;
+import org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath;
 import org.eclipse.cdt.managedbuilder.core.IManagedConfigElement;
 import org.eclipse.cdt.managedbuilder.core.IOption;
 import org.eclipse.cdt.managedbuilder.core.IOptionCategory;
@@ -1092,4 +1093,10 @@ public class ToolReference implements IToolReference {
 		return command;
 	}
 
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.core.build.managed.ITool#getEnvVarBuildPaths()
+	 */
+	public IEnvVarBuildPath[] getEnvVarBuildPaths(){
+		return null;
+	}
 }
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/BuildEnvVar.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/BuildEnvVar.java
new file mode 100644
index 00000000000..0dbc320f6c5
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/BuildEnvVar.java
@@ -0,0 +1,80 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+
+/**
+ * a trivial implementation of the IBuildEnvironmentVariable
+ * 
+ * @since 3.0
+ */
+public class BuildEnvVar implements IBuildEnvironmentVariable {
+	protected String fName;
+	protected String fValue;
+	protected String fDelimiter;
+	protected int fOperation;
+	
+	public BuildEnvVar(String name, String value, int op, String delimiter){
+		fName = name;
+		fOperation = op;
+		fValue = value;
+		fDelimiter = delimiter;
+	}
+	
+	protected BuildEnvVar(){
+		
+	}
+	
+	public BuildEnvVar(String name){
+		this(name,null,ENVVAR_REPLACE,null);
+	}
+	
+	public BuildEnvVar(String name, String value){
+		this(name,value,ENVVAR_REPLACE,null);	
+	}
+
+	public BuildEnvVar(String name, String value, String delimiter){
+		this(name,value,ENVVAR_REPLACE,delimiter);	
+	}
+	
+	public BuildEnvVar(IBuildEnvironmentVariable var){
+		this(var.getName(),var.getValue(),var.getOperation(),var.getDelimiter());	
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable#getName()
+	 */
+	public String getName(){
+		return fName;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable#getValue()
+	 */
+	public String getValue(){
+		return fValue;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable#getOperation()
+	 */
+	public int getOperation(){
+		return fOperation;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable#getDelimiter()
+	 */
+	public String getDelimiter(){
+		return fDelimiter;
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/DefaultContextInfo.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/DefaultContextInfo.java
new file mode 100644
index 00000000000..6ef9d314979
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/DefaultContextInfo.java
@@ -0,0 +1,101 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IManagedProject;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.resources.ResourcesPlugin;
+
+/**
+ * The default implementation of the IContextInfo used by the Environment Variable Provider
+ * Used to represent the Configuration, Project, Workspace and Eclipse environment contexts
+ * 
+ * @since 3.0
+ */
+public class DefaultContextInfo implements IContextInfo{
+	private Object fContextObject;
+	private IEnvironmentVariableSupplier fContextSuppliers[];
+	
+	/**
+	 * This constructor is used to create the default context info given a context object
+	 * 
+	 * @param context
+	 */
+	public DefaultContextInfo(Object context){
+		fContextObject = context;
+	}
+	
+	protected DefaultContextInfo(Object context, IEnvironmentVariableSupplier suppliers[]){
+		fContextSuppliers = suppliers;
+		fContextObject = context;
+	}
+	
+	/*
+	 * answers the list of suppliers that should be used for the given context 
+	 */
+	protected IEnvironmentVariableSupplier[] getSuppliers(Object context){
+		IEnvironmentVariableSupplier suppliers[];
+		if(context == null)
+			suppliers = new IEnvironmentVariableSupplier[]{EnvironmentVariableProvider.fEclipseSupplier};
+		else if(context instanceof IWorkspace)
+			suppliers = new IEnvironmentVariableSupplier[]{EnvironmentVariableProvider.fUserSupplier};
+		else if(context instanceof IManagedProject)
+			suppliers = new IEnvironmentVariableSupplier[]{EnvironmentVariableProvider.fUserSupplier,EnvironmentVariableProvider.fExternalSupplier};
+		else if(context instanceof IConfiguration)
+			suppliers = new IEnvironmentVariableSupplier[]{EnvironmentVariableProvider.fUserSupplier,EnvironmentVariableProvider.fExternalSupplier,EnvironmentVariableProvider.fMbsSupplier};
+		else
+			suppliers = null;
+		return suppliers;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.IContextInfo#getNext()
+	 */
+	public IContextInfo getNext(){
+		DefaultContextInfo next = null;
+		if(fContextObject == null)
+			next = null;
+		else if(fContextObject instanceof IWorkspace)
+			next = new DefaultContextInfo(null);
+		else if(fContextObject instanceof IManagedProject)
+			next = new DefaultContextInfo(ResourcesPlugin.getWorkspace());
+		else if(fContextObject instanceof IConfiguration)
+			next = new DefaultContextInfo(((IConfiguration)fContextObject).getManagedProject());
+		else
+			next = null;
+
+		if(next != null && next.getSuppliers() == null)
+			next = null;
+		return next;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.IContextInfo#getSuppliers()
+	 */
+	public IEnvironmentVariableSupplier[] getSuppliers(){
+		if(fContextSuppliers == null)
+			fContextSuppliers = getSuppliers(fContextObject);
+		return fContextSuppliers;
+	}
+	
+	protected void setSuppliers(IEnvironmentVariableSupplier suppliers[]){
+		fContextSuppliers = suppliers;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.IContextInfo#getContext()
+	 */
+	public Object getContext(){
+		return fContextObject;
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EclipseEnvironmentSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EclipseEnvironmentSupplier.java
new file mode 100644
index 00000000000..380b41ea6a3
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EclipseEnvironmentSupplier.java
@@ -0,0 +1,62 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.Enumeration;
+import java.util.Properties;
+
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.cdt.utils.spawner.EnvironmentReader;
+
+/**
+ * This is the Environment Variable Supplier used to supply variables
+ * defined in eclipse environment
+ * 
+ * @since 3.0
+ */
+public class EclipseEnvironmentSupplier implements IEnvironmentVariableSupplier {
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariable()
+	 */
+	public IBuildEnvironmentVariable getVariable(String name, Object context) {
+		if(context == null){
+			String value = EnvironmentReader.getEnvVar(name);
+			if(value == null)
+				return null;
+			return new BuildEnvVar(name,value,IBuildEnvironmentVariable.ENVVAR_REPLACE,null);
+		}
+		return null;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariables()
+	 */
+	public IBuildEnvironmentVariable[] getVariables(Object context) {
+		if(context == null){
+			Properties values = EnvironmentReader.getEnvVars();
+			if(values == null)
+				return null;
+
+			IBuildEnvironmentVariable variables[] = new IBuildEnvironmentVariable[values.size()];
+			Enumeration en = values.propertyNames();
+			for( int i = 0; i < variables.length ; i++){
+				String name = (String)en.nextElement();
+				String value = values.getProperty(name);
+				variables[i] = new BuildEnvVar(name,value,IBuildEnvironmentVariable.ENVVAR_REPLACE,null);
+			}
+			return variables;
+		}
+		return null;
+	}
+
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarCollector.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarCollector.java
new file mode 100644
index 00000000000..71f27632d6f
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarCollector.java
@@ -0,0 +1,114 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+
+/**
+ * This class implements the "merging" functionality of environment variables
+ * Used by the EnvironmentVariableProvider to "merge" the sets of macros returned
+ * by different suppliers into one set returned to the user
+ *  
+ * @since 3.0
+ *
+ */
+public class EnvVarCollector {
+	private Map fMap = null;
+	public EnvVarCollector(){
+		
+	}
+	
+	/**
+	 * adds an array of environment variables to the set of variables held by this collector
+	 * performing environment variable operations
+	 * @param vars
+	 */
+	public void add(IBuildEnvironmentVariable vars[]){
+		if(vars == null)
+			return;
+		boolean isCaseInsensitive = !EnvironmentVariableProvider.getDefault().isVariableCaseSensitive();
+		for(int i = 0; i < vars.length; i ++) {
+			IBuildEnvironmentVariable var = vars[i];
+			String name = var.getName();
+			if(isCaseInsensitive)
+				name = name.toUpperCase();
+			
+			boolean noCheck = false;
+			
+			if(fMap == null){
+				noCheck = true;
+				fMap = new HashMap();
+			}
+			
+			if(noCheck)
+				fMap.put(name,var);
+			else {
+				IBuildEnvironmentVariable prevVar = (IBuildEnvironmentVariable)fMap.remove(name);
+				fMap.put(name,EnvVarOperationProcessor.performOperation(prevVar,var));
+			}
+		}
+	}
+	
+	/**
+	 * Returns an array of variables held by this collector
+	 * 
+	 * @param includeRemoved true if removed variables should be included in the resulting array
+	 * @return IBuildEnvironmentVariable[]
+	 */
+	public IBuildEnvironmentVariable[] toArray(boolean includeRemoved){
+		if(fMap == null)
+			return new IBuildEnvironmentVariable[0];
+		Collection values = fMap.values();
+		List list = new ArrayList();
+		Iterator iter = values.iterator();
+		while(iter.hasNext()){
+			IBuildEnvironmentVariable var = (IBuildEnvironmentVariable)iter.next();
+			if(var != null && 
+					(includeRemoved || var.getOperation() != IBuildEnvironmentVariable.ENVVAR_REMOVE))
+				list.add(var);
+		}
+		return (IBuildEnvironmentVariable[])list.toArray(new IBuildEnvironmentVariable[list.size()]);
+	}
+	
+	/**
+	 * Returns a variable of a given name held by this collector
+	 * 
+	 * @param name a variable name
+	 * @return IBuildEnvironmentVariable
+	 */
+	public IBuildEnvironmentVariable getVariable(String name){
+		if(fMap == null)
+			return null;
+		
+		if(!EnvironmentVariableProvider.getDefault().isVariableCaseSensitive())
+			name = name.toUpperCase();
+
+		return (IBuildEnvironmentVariable)fMap.get(name);
+	}
+	
+	/**
+	 * Returns an array of variables held by this collector
+	 * The call to this method is equivalent of calling toArray(true)
+	 * 
+	 * @return IBuildEnvironmentVariable[]
+	 */
+	public IBuildEnvironmentVariable[] getVariables(){
+		return toArray(true);
+	}
+
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarOperationProcessor.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarOperationProcessor.java
new file mode 100644
index 00000000000..c489219f93d
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvVarOperationProcessor.java
@@ -0,0 +1,251 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+
+/**
+ * This is an utility class that implements environment variable operations 
+ * functionality: append, prepend, replace and remove
+ * 
+ * @since 3.0
+ */
+public class EnvVarOperationProcessor {
+	private static final String EMPTY_STRING = "";   //$NON-NLS-1$
+	
+	/**
+	 * performs the environment variable operation given an initial variable and
+	 * a variable representing an operation to be performed
+	 * Returns a new variable the represents the result of a performed operation 
+	 * 
+	 * @param initial the initial variable
+	 * @param added the variable that specifies an operation to be performed on the
+	 * initial variable value 
+	 * @return the new variable the represents the result of a performed operation 
+	 */
+	static public IBuildEnvironmentVariable performOperation(IBuildEnvironmentVariable initial, IBuildEnvironmentVariable added){
+		if(initial == null){
+			return added;
+		}
+		if(added == null)
+			return initial;
+		
+		String name = added.getName();
+		
+		switch(added.getOperation()){
+		case IBuildEnvironmentVariable.ENVVAR_REMOVE:
+			return new BuildEnvVar(name,null,IBuildEnvironmentVariable.ENVVAR_REMOVE,null);
+		case IBuildEnvironmentVariable.ENVVAR_APPEND:{
+				String delimiter = added.getDelimiter();
+				return new BuildEnvVar(name,
+						performAppend(initial.getValue(),added.getValue(),delimiter),
+//						IBuildEnvironmentVariable.ENVVAR_APPEND,
+						delimiter);
+			}
+		case IBuildEnvironmentVariable.ENVVAR_PREPEND:{
+				String delimiter = added.getDelimiter();
+				return new BuildEnvVar(name,
+						performPrepend(initial.getValue(),added.getValue(),delimiter),
+//						IBuildEnvironmentVariable.ENVVAR_PREPEND,
+						delimiter);
+			}
+		case IBuildEnvironmentVariable.ENVVAR_REPLACE:
+		default:
+			return new BuildEnvVar(added.getName(),added.getValue(),added.getDelimiter());
+		}
+	}
+
+	/**
+	 * performs append or prepend given an initial String, a string to be appended/prepended and a delimiter
+	 * Returns a String representing the result of the operation
+	 * @param initialValue
+	 * @param addValue
+	 * @param delimiter
+	 * @param prepend
+	 * @return String
+	 */
+	static public String performAppendPrepend(String initialValue, String addValue, String delimiter, boolean prepend){
+		if(initialValue == null)
+			return addValue;
+		if(addValue == null)
+			return initialValue;
+		
+		if(delimiter == null || "".equals(delimiter)){   //$NON-NLS-1$
+			return prepend ? addValue + initialValue : initialValue + addValue;
+		}
+		
+		List value = convertToList(initialValue, delimiter);
+		List added = convertToList(addValue, delimiter);
+
+		value = removeDuplicates(value, added);
+		
+		if(prepend)
+			value.addAll(0,added);
+		else
+			value.addAll(added);
+		
+		return convertToString(value, delimiter);
+	}
+	
+	/**
+	 * performs append given an initial String, a string to be appended and a delimiter
+	 * Returns a String representing the result of the operation
+	 * @param initialValue
+	 * @param addValue
+	 * @param delimiter
+	 * @return String
+	 */
+	static public String performAppend(String initialValue, String addValue, String delimiter){
+		return performAppendPrepend(initialValue,addValue,delimiter,false);
+	}
+	
+	/**
+	 * performs prepend given an initial String, a string to be prepended and a delimiter
+	 * Returns a String representing the result of the operation
+	 * @param initialValue
+	 * @param addValue
+	 * @param delimiter
+	 * @return String
+	 */
+	static public String performPrepend(String initialValue, String addValue, String delimiter){
+		return performAppendPrepend(initialValue,addValue,delimiter,true);
+	}
+	
+	/**
+	 * performs an environment variable operation
+	 * Returns String representing the result of the operation
+	 * @param initialValue
+	 * @param newValue
+	 * @param delimiter
+	 * @param op
+	 * @return String
+	 */
+	static public String performOperation(String initialValue, String newValue, String delimiter, int op){
+		switch(op){
+		case IBuildEnvironmentVariable.ENVVAR_REMOVE:
+			return null;
+		case IBuildEnvironmentVariable.ENVVAR_PREPEND:
+			return performPrepend(initialValue,newValue,delimiter);
+		case IBuildEnvironmentVariable.ENVVAR_APPEND:
+			return performAppend(initialValue,newValue,delimiter);
+		case IBuildEnvironmentVariable.ENVVAR_REPLACE:	
+		default:
+			return initialValue;
+		}
+	}
+
+	/**
+	 * Converts a given value to string using a delimiter passed to this method
+	 * @param value
+	 * @param delimiter
+	 * @return
+	 */
+	static public List convertToList(String value, String delimiter){
+		List list = new ArrayList();
+		int delLength = delimiter.length();
+		int valLength = value.length();
+
+		if(delLength == 0){
+			list.add(value);
+		}
+		else{
+			int start = 0;
+			int stop;
+			while(start < valLength){
+				stop = value.indexOf(delimiter,start);
+				if(stop == -1)
+					stop = valLength;
+				String subst = value.substring(start,stop);
+				list.add(subst);
+				start = stop + delLength;
+			}
+		}
+
+		return list;
+	}
+	
+	/*
+	 * removes duplicates
+	 */
+	static public List removeDuplicates(List value, List duplicates){
+		List list = new ArrayList();
+		Iterator valueIter = value.iterator();
+		while(valueIter.hasNext()){
+			String curVal = (String)valueIter.next();
+			boolean duplFound = false;
+			Iterator duplicatesIter = duplicates.iterator();
+			while(duplicatesIter.hasNext()){
+				String curDupl = (String)duplicatesIter.next();
+				if(curVal.equals(curDupl)){
+					duplFound = true;
+					break;
+				}
+			}
+			if(!duplFound)
+				list.add(curVal);
+		}
+		return list;
+	}
+	
+	/**
+	 * Converts list to a single String using a given delimiter to separate
+	 * the list value in the resulting String
+	 * @param list
+	 * @param delimiter
+	 * @return String
+	 */
+	static public String convertToString(List list, String delimiter){
+		Iterator iter = list.iterator();
+		StringBuffer buffer = new StringBuffer();
+		
+		while(iter.hasNext()){
+			buffer.append((String)iter.next());
+			
+			if(iter.hasNext())
+				buffer.append(delimiter);
+		}
+		
+		return buffer.toString();
+	}
+	
+	/*
+	 * concatenetes two Strings
+	 * Returns a resulting string
+	 */
+	static private String concatenateStrings(String str1, String str2, String delimiter){
+		if(str1 == null || "".equals(str1))   //$NON-NLS-1$
+			return str2;
+		if(str2 == null || "".equals(str2))   //$NON-NLS-1$
+			return str1;
+		
+		return str1 + delimiter + str2;
+	}
+	
+	/*
+	 * normalizes the variable name. That is: removes prepended and appended spaces
+	 * and converts the name to upper-case for Win32 systems
+	 * @return the normalized name or <code>null</code> in case the name is not valid
+	 */
+	static public String normalizeName(String name){
+		if(name == null)
+			return null;
+		if("".equals(name = name.trim()))   //$NON-NLS-1$
+			return null;
+		if(!ManagedBuildManager.getEnvironmentVariableProvider().isVariableCaseSensitive())
+			name = name.toUpperCase();
+		return name;
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvironmentVariableProvider.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvironmentVariableProvider.java
new file mode 100644
index 00000000000..e5c251bfc06
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/EnvironmentVariableProvider.java
@@ -0,0 +1,513 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.HashSet;
+import java.util.Iterator;
+import java.util.List;
+
+import org.eclipse.cdt.managedbuilder.core.IBuildPathResolver;
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath;
+import org.eclipse.cdt.managedbuilder.core.ITool;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuilderCorePlugin;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentBuildPathsChangeListener;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.core.runtime.QualifiedName;
+
+/**
+ * This class implements the IEnvironmentVariableProvider interface and provides all
+ * build environment funvtionality to the MBS
+ * 
+ * @since 3.0
+ *
+ */
+public class EnvironmentVariableProvider implements
+		IEnvironmentVariableProvider {
+	private static final QualifiedName fBuildPathVarProperty = new QualifiedName(ManagedBuilderCorePlugin.getUniqueIdentifier(), "buildPathVar");	//$NON-NLS-1$
+
+	private static final String DELIMITER_WIN32 = ";";  //$NON-NLS-1$
+	private static final String DELIMITER_UNIX = ":";  //$NON-NLS-1$
+	
+	private static EnvironmentVariableProvider fInstance = null;
+	private List fListeners = null;
+	
+	private StoredBuildPathEnvironmentContainer fIncludeStoredBuildPathVariables;
+	private StoredBuildPathEnvironmentContainer fLibraryStoredBuildPathVariables;
+	
+	public static final UserDefinedEnvironmentSupplier fUserSupplier = new UserDefinedEnvironmentSupplier();
+	public static final ExternalExtensionEnvironmentSupplier fExternalSupplier = new ExternalExtensionEnvironmentSupplier();
+	public static final MbsEnvironmentSupplier fMbsSupplier = new MbsEnvironmentSupplier();
+	public static final EclipseEnvironmentSupplier fEclipseSupplier = new EclipseEnvironmentSupplier();
+
+	/**
+	 * This class is used by the EnvironmentVariableProvider to calculate the build paths
+	 * in case a tool-integrator did not provide the special logic for obtaining the build 
+	 * paths from environment variable values
+	 * 
+	 * @since 3.0
+	 *
+	 */
+	static public class DefaultBuildPathResolver implements IBuildPathResolver {
+		private String fDelimiter;
+		
+		public DefaultBuildPathResolver(String delimiter){
+			fDelimiter = delimiter;
+		}
+
+		public String[] resolveBuildPaths(int pathType, String variableName,
+				String variableValue, IConfiguration configuration) {
+			
+			if(fDelimiter == null || "".equals(fDelimiter)) //$NON-NLS-1$
+				return new String[]{variableValue};
+			
+			List list = EnvVarOperationProcessor.convertToList(variableValue,fDelimiter);
+			return (String[]) list.toArray(new String[list.size()]);
+		}
+
+	}
+
+	EnvironmentVariableProvider(){
+		
+	}
+
+	public static EnvironmentVariableProvider getDefault(){
+		if(fInstance == null)
+			fInstance = new EnvironmentVariableProvider();
+		return fInstance;
+	}
+	
+	/*
+	 * returns a variable of a given name or null
+	 * the context information is taken from the contextInfo passed
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.IContextInfo
+	 */
+	public IBuildEnvironmentVariable getVariable(String variableName,
+			IContextInfo contextInfo, boolean includeParentLevels){
+
+		if(contextInfo == null)
+			return null;
+		if(variableName == null || "".equals(variableName = variableName.trim())) //$NON-NLS-1$
+			return null;
+
+
+		IContextInfo infos[] = getAllContextInfos(contextInfo);
+		variableName = adjustName(variableName);
+		
+		if(!includeParentLevels){
+			IEnvironmentVariableSupplier suppliers[] = infos[0].getSuppliers();
+			boolean bVarFound = false;
+			for(int i = 0; i < suppliers.length; i++){
+				if(suppliers[i].getVariable(variableName,infos[0].getContext()) != null){
+					bVarFound = true;
+					break;
+				}
+			}
+			if(!bVarFound)
+				return null;
+		}
+
+		IBuildEnvironmentVariable variable = null;
+		
+		for(int i = infos.length-1 ; i >=0 ; i-- ) {
+			IContextInfo info = infos[i];
+			IEnvironmentVariableSupplier suppliers[] = info.getSuppliers();
+			
+			for(int j = suppliers.length-1 ; j >= 0 ; j-- ) {
+				IEnvironmentVariableSupplier supplier = suppliers[j];
+				IBuildEnvironmentVariable var = supplier.getVariable(variableName,info.getContext());
+				
+				if(var == null)
+					continue;
+				
+				if(variable == null)
+					variable = var;
+				else
+					variable = EnvVarOperationProcessor.performOperation(variable,var);
+			}
+		}
+	
+		if(variable != null && variable.getOperation() == IBuildEnvironmentVariable.ENVVAR_REMOVE)
+			variable = null;
+		return variable;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getVariable()
+	 */
+	public IBuildEnvironmentVariable getVariable(String variableName,
+			Object level, boolean includeParentLevels) {
+
+		if(variableName == null || "".equals(variableName)) //$NON-NLS-1$
+			return null;
+		
+		IBuildEnvironmentVariable var = getVariable(variableName,getContextInfo(level),includeParentLevels);
+		if(level instanceof IConfiguration)
+			checkBuildPathVariable((IConfiguration)level,variableName,var);
+		return var;
+	}
+	
+	public String adjustName(String name){
+		if(!isVariableCaseSensitive())
+			name = name.toUpperCase();
+		return name;
+	}
+	
+	/*
+	 * returns the context info that should be used for the given level
+	 * or null if the the given level is not supported
+	 */
+	protected IContextInfo getContextInfo(Object level){
+		DefaultContextInfo info = new DefaultContextInfo(level);
+		if(info.getSuppliers() == null)
+			return null;
+		return info;
+	}
+	
+	/*
+	 * returns a list of defined variables.
+	 * the context information is taken from the contextInfo passed
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.IContextInfo
+	 */
+	public EnvVarCollector getVariables(IContextInfo contextInfo,
+			boolean includeParentLevels) {
+		if(contextInfo == null)
+			return null;
+		
+		IContextInfo infos[] = getAllContextInfos(contextInfo);
+		HashSet set = null;
+		
+		if(!includeParentLevels){
+			IEnvironmentVariableSupplier suppliers[] = infos[0].getSuppliers();
+			set = new HashSet();
+			for(int i = 0; i < suppliers.length; i++){
+				IBuildEnvironmentVariable vars[] = suppliers[i].getVariables(infos[0].getContext());
+				if(vars != null){
+					for(int j = 0; j < vars.length; j++){
+						set.add(
+								adjustName(vars[j].
+										getName())
+										);
+					}
+				}
+			}
+			if(set.size() == 0)
+				return new EnvVarCollector();
+		}
+		
+		EnvVarCollector envVarSet = new EnvVarCollector();
+		
+		for(int i = infos.length-1 ; i >=0 ; i-- ) {
+			IContextInfo info = infos[i];
+			IEnvironmentVariableSupplier suppliers[] = info.getSuppliers();
+			
+			for(int j = suppliers.length-1 ; j >= 0 ; j-- ) {
+				IEnvironmentVariableSupplier supplier = suppliers[j];
+				IBuildEnvironmentVariable vars[] = null;
+				if(set != null){
+					List varList = new ArrayList();
+					Iterator iter = set.iterator();
+					
+					while(iter.hasNext()){
+						IBuildEnvironmentVariable var = supplier.getVariable((String)iter.next(),info.getContext());
+						if(var != null)
+							varList.add(var);
+					}
+					vars = (IBuildEnvironmentVariable[])varList.toArray(new IBuildEnvironmentVariable[varList.size()]);
+				}
+				else{
+					 vars = supplier.getVariables(info.getContext());
+				}
+				envVarSet.add(vars);
+			}
+		}
+	
+		return envVarSet;		
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getVariables()
+	 */
+	public IBuildEnvironmentVariable[] getVariables(Object level,
+			boolean includeParentLevels) {
+		
+		EnvVarCollector varSet = getVariables(getContextInfo(level),includeParentLevels);
+		
+		if(level instanceof IConfiguration)
+			checkBuildPathVariables((IConfiguration)level,varSet);
+
+		if(varSet != null)
+			return varSet.toArray(false);
+		return null;
+	}
+	
+	/*
+	 * returns an array of the IContextInfo that holds the context informations
+	 * starting from the one passed to this method and including all subsequent parents
+	 */
+	private IContextInfo[] getAllContextInfos(IContextInfo contextInfo){
+		if(contextInfo == null)
+			return null;
+			
+		List list = new ArrayList();
+	
+		list.add(contextInfo);
+			
+		while((contextInfo = contextInfo.getNext()) != null)
+			list.add(contextInfo);
+		
+		return (IContextInfo[])list.toArray(new IContextInfo[list.size()]);
+	}
+	
+	private boolean isWin32(){
+		String os = System.getProperty("os.name").toLowerCase(); //$NON-NLS-1$
+		if (os.startsWith("windows ")) //$NON-NLS-1$
+			return true;
+		return false;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getDefaultDelimiter()
+	 */
+	public String getDefaultDelimiter() {
+		return isWin32() ? DELIMITER_WIN32 : DELIMITER_UNIX;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#isVariableCaseSensitive()
+	 */
+	public boolean isVariableCaseSensitive() {
+		return !isWin32();
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getSuppliers()
+	 */
+	public IEnvironmentVariableSupplier[] getSuppliers(Object level) {
+		IContextInfo info = getContextInfo(level);
+		if(info != null)
+			return info.getSuppliers();
+		return null;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getBuildPaths()
+	 */
+	public String[] getBuildPaths(IConfiguration configuration,
+			int buildPathType) {
+		ITool tools[] = configuration.getFilteredTools();
+		List list = new ArrayList();
+		
+		for(int i = 0; i < tools.length; i++){
+			IEnvVarBuildPath pathDescriptors[] = tools[i].getEnvVarBuildPaths();
+			
+			if(pathDescriptors == null || pathDescriptors.length == 0)
+				continue;
+			
+			for(int j = 0; j < pathDescriptors.length; j++){
+				IEnvVarBuildPath curPathDes = pathDescriptors[j];
+				if(curPathDes.getType() != buildPathType)
+					continue;
+				
+				String vars[] = curPathDes.getVariableNames();
+				if(vars == null || vars.length == 0)
+					continue;
+				
+				IBuildPathResolver pathResolver = curPathDes.getBuildPathResolver();
+				if(pathResolver == null){
+					String delimiter = curPathDes.getPathDelimiter();
+					if(delimiter == null)
+						delimiter = getDefaultDelimiter();
+					pathResolver = new DefaultBuildPathResolver(delimiter);
+				}
+				
+				for(int k = 0; k < vars.length; k++){
+					String varName = vars[k];
+					
+					IBuildEnvironmentVariable var = getVariable(varName,configuration,true);
+					if(var == null)
+						continue;
+					
+					String varValue = var.getValue();
+					String paths[] = pathResolver.resolveBuildPaths(buildPathType,varName,varValue,configuration);
+					if(paths != null && paths.length != 0)
+						list.addAll(Arrays.asList(paths));
+				}
+			}
+		}
+		
+		return (String[])list.toArray(new String[list.size()]);
+	}
+	
+	/*
+	 * returns a list of registered listeners
+	 */
+	private List getListeners(){
+		if(fListeners == null)
+			fListeners = new ArrayList();
+		return fListeners;
+	}
+	
+	/*
+	 * notifies registered listeners
+	 */
+	private void notifyListeners(IConfiguration configuration, int buildPathType){
+		List listeners = getListeners();
+		Iterator iterator = listeners.iterator();
+		while(iterator.hasNext())
+			((IEnvironmentBuildPathsChangeListener)iterator.next()).buildPathsChanged(configuration,buildPathType);
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#subscribe()
+	 */
+	public synchronized void subscribe(IEnvironmentBuildPathsChangeListener listener) {
+		if(listener == null)
+			return;
+		
+		List listeners = getListeners();
+		
+		if(!listeners.contains(listener))
+			listeners.add(listener);
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#unsubscribe()
+	 */
+	public synchronized void unsubscribe(IEnvironmentBuildPathsChangeListener listener) {
+		if(listener == null)
+			return;
+		
+		List listeners = getListeners();
+		
+		listeners.remove(listener);
+	}
+	
+	/*
+	 * returns true if the first passed contextInfo is the child of the second one
+	 */
+	public boolean checkParentContextRelation(IContextInfo child, IContextInfo parent){
+		if(child == null || parent == null)
+			return false;
+
+		IContextInfo enumInfo = child;
+		do{
+			if(parent.getContext() == enumInfo.getContext())
+				return true;
+		}while((enumInfo = enumInfo.getNext()) != null);
+		return false;
+	}
+	
+	/*
+	 * performs a check of the build path variables for the given configuration
+	 * If the build variables are changed, the notification is sent
+	 */
+	public void checkBuildPathVariables(IConfiguration configuration){
+		checkBuildPathVariables(configuration,getVariables(getContextInfo(configuration),true));
+	}
+
+	/*
+	 * performs a check of the build path variables of the specified type
+	 * for the given configuration
+	 * If the build variables are changed, the notification is sent
+	 */
+	public void checkBuildPathVariables(IConfiguration configuration,int buildPathType){
+		checkBuildPathVariables(configuration,buildPathType,getVariables(getContextInfo(configuration),true));
+	}
+
+	/*
+	 * performs a check of the build path variables
+	 * for the given configuration given the set of the variables 
+	 * defined for this configuration
+	 * If the build variables are changed, the notification is sent
+	 */
+	protected void checkBuildPathVariables(IConfiguration configuration, EnvVarCollector varSet){
+		checkBuildPathVariables(configuration,IEnvVarBuildPath.BUILDPATH_INCLUDE,varSet);
+		checkBuildPathVariables(configuration,IEnvVarBuildPath.BUILDPATH_LIBRARY,varSet);
+	}
+
+	/*
+	 * performs a check of whether the given variable is the build path variable
+	 * and if true checks whether it is changed.
+	 * In the case of it is changed all other build path variables are checked
+	 * and notification is sent.
+	 * If it is not changed, other build path variables are not checked
+	 * In the case of the given variable is not the build path one, this method does nothing
+	 */
+	protected void checkBuildPathVariable(IConfiguration configuration, String varName, IBuildEnvironmentVariable var){
+		checkBuildPathVariable(configuration, IEnvVarBuildPath.BUILDPATH_INCLUDE, varName, var);
+		checkBuildPathVariable(configuration, IEnvVarBuildPath.BUILDPATH_LIBRARY, varName, var);
+	}
+
+	/*
+	 * performs a check of whether the given variable is the build path variable
+	 * of the specified type and if true checks whether it is changed.
+	 * In the case of it is changed all other build path variables of that type are checked
+	 * and notification is sent.
+	 * If it is not changed, other build path variables are not checked
+	 * In the case of the given variable is not the build path one, this method does nothing
+	 */
+	protected void checkBuildPathVariable(IConfiguration configuration, int buildPathType, String varName, IBuildEnvironmentVariable var){
+		StoredBuildPathEnvironmentContainer buildPathVars = getStoredBuildPathVariables(buildPathType);
+		if(buildPathVars == null)
+			return;
+		if(buildPathVars.isVariableChanged(varName,var,configuration)){
+			buildPathVars.synchronize(getVariables(getContextInfo(configuration),true),configuration);
+			notifyListeners(configuration, buildPathType);
+		}
+	}
+
+	/*
+	 * performs a check of the build path variables of the specified type
+	 * for the given configuration given the set of the variables 
+	 * defined for this configuration. 
+	 * If the build variables are changed, the notification is sent
+	 */
+	protected void checkBuildPathVariables(IConfiguration configuration, int buildPathType, EnvVarCollector varSet){
+		StoredBuildPathEnvironmentContainer buildPathVars = getStoredBuildPathVariables(buildPathType);
+		if(buildPathVars == null)
+			return;
+		if(buildPathVars.checkBuildPathChange(varSet,configuration)){
+			notifyListeners(configuration, buildPathType);
+		}
+	}
+	
+	/*
+	 * returns the container of the build variables of the specified type
+	 */
+	protected StoredBuildPathEnvironmentContainer getStoredBuildPathVariables(int buildPathType){
+		return buildPathType == IEnvVarBuildPath.BUILDPATH_LIBRARY ?
+				getStoredLibraryBuildPathVariables() :
+				getStoredIncludeBuildPathVariables();
+	}
+	
+	/*
+	 * returns the container of the Include path variables
+	 */
+	protected StoredBuildPathEnvironmentContainer getStoredIncludeBuildPathVariables(){
+		if(fIncludeStoredBuildPathVariables == null)
+			fIncludeStoredBuildPathVariables = new StoredBuildPathEnvironmentContainer(IEnvVarBuildPath.BUILDPATH_INCLUDE);
+		return fIncludeStoredBuildPathVariables;
+	}
+
+	/*
+	 * returns the container of the Library path variables
+	 */
+	protected StoredBuildPathEnvironmentContainer getStoredLibraryBuildPathVariables(){
+		if(fLibraryStoredBuildPathVariables == null)
+			fLibraryStoredBuildPathVariables = new StoredBuildPathEnvironmentContainer(IEnvVarBuildPath.BUILDPATH_LIBRARY);
+		return fLibraryStoredBuildPathVariables;
+	}	
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/ExternalExtensionEnvironmentSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/ExternalExtensionEnvironmentSupplier.java
new file mode 100644
index 00000000000..a15b626f273
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/ExternalExtensionEnvironmentSupplier.java
@@ -0,0 +1,230 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IManagedProject;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IConfigurationEnvironmentVariableSupplier;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.cdt.managedbuilder.envvar.IProjectEnvironmentVariableSupplier;
+
+/**
+ * This is the Environment Variable Supplier used to supply variables
+ * defined by the tool-integrator
+ * 
+ * @since 3.0
+ */
+public class ExternalExtensionEnvironmentSupplier implements
+		IEnvironmentVariableSupplier {
+	private static final String fNonOverloadableVariables[] = new String[]{
+			//tool-integrators not allowed currently to override the "CWD" and "PWD" variables
+			EnvVarOperationProcessor.normalizeName("CWD"),   //$NON-NLS-1$
+			EnvVarOperationProcessor.normalizeName("PWD")	  //$NON-NLS-1$
+		};
+
+	/**
+	 * EnvironmentVariableProvider passed to the tool-integrator provided
+	 * suppliers.
+	 * Accepts only contexts lower than the one passed to a suppler  
+	 * 
+	 * @since 3.0
+	 */
+	private class ExtensionEnvVarProvider extends EnvironmentVariableProvider{
+		private IContextInfo fStartInfo;
+		private Object fStartLevel;
+		private boolean fStartInitialized;
+		
+		public ExtensionEnvVarProvider(Object level){
+			fStartLevel = level;
+		}
+		
+		/* (non-Javadoc)
+		 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider#getVariable(java.lang.String, java.lang.Object, boolean)
+		 */
+		public IBuildEnvironmentVariable getVariable(String variableName,
+				Object level, boolean includeParentLevels) {
+			if(getValidName(variableName) == null)
+				return null;
+			return super.getVariable(variableName,level,includeParentLevels);
+		}
+
+		public IBuildEnvironmentVariable[] getVariables(Object level, boolean includeParentLevels) {
+			return filterVariables(super.getVariables(level,includeParentLevels));
+		}
+	
+		/* (non-Javadoc)
+		 * @see org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider#getContextInfo(java.lang.Object)
+		 */
+		protected IContextInfo getContextInfo(Object level){
+			IContextInfo startInfo = getStartInfo();
+			if(level == fStartLevel)
+				return startInfo;
+			
+			IContextInfo info = super.getContextInfo(level);
+			if(info == null)
+				return null;
+			
+			if(checkParentContextRelation(startInfo,info))
+				return info;
+			return null;
+		}
+		
+		protected IContextInfo getStartInfo(){
+			if(fStartInfo == null && !fStartInitialized){
+				IContextInfo info = super.getContextInfo(fStartLevel);
+				if(info != null){
+					IEnvironmentVariableSupplier suppliers[] = info.getSuppliers();
+					suppliers = filterValidSuppliers(suppliers);
+					if(suppliers != null)
+						fStartInfo = new DefaultContextInfo(fStartLevel,suppliers);
+					else
+						fStartInfo = info.getNext();
+					fStartInitialized = true;
+				}
+				fStartInitialized = true;
+			}
+			return fStartInfo;
+		}
+		
+		
+		/* (non-Javadoc)
+		 * @see org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider#getStoredBuildPathVariables(int)
+		 */
+		protected StoredBuildPathEnvironmentContainer getStoredBuildPathVariables(int buildPathType){
+			return null;
+		}
+		
+		/* (non-Javadoc)
+		 * @see org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider#getStoredIncludeBuildPathVariables()
+		 */
+		protected StoredBuildPathEnvironmentContainer getStoredIncludeBuildPathVariables(){
+			return null;
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.cdt.managedbuilder.internal.envvar.EnvironmentVariableProvider#getStoredLibraryBuildPathVariables()
+		 */
+		protected StoredBuildPathEnvironmentContainer getStoredLibraryBuildPathVariables(){
+			return null;
+		}
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariable()
+	 */
+	public IBuildEnvironmentVariable getVariable(String name, Object context) {
+		if(context == null)
+			return null;
+		if((name = getValidName(name)) == null)
+			return null;
+			
+		else if(context instanceof IConfiguration){
+			IConfiguration cfg = (IConfiguration)context;
+			IConfigurationEnvironmentVariableSupplier supplier = cfg.getEnvironmentVariableSupplier();
+			if(supplier == null)
+				return null;
+			return supplier.getVariable(name,cfg,new ExtensionEnvVarProvider(context));
+		}
+		else if (context instanceof IManagedProject) {
+			IManagedProject project = (IManagedProject)context; 
+			IProjectEnvironmentVariableSupplier supplier = project.getProjectType().getEnvironmentVariableSupplier();
+			if(supplier == null)
+				return null;
+			return supplier.getVariable(name,project,new ExtensionEnvVarProvider(context));
+		}
+		return null;
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariables()
+	 */
+	public IBuildEnvironmentVariable[] getVariables(Object context) {
+		if(context == null)
+			return null;
+		IBuildEnvironmentVariable variables[] = null;
+		if(context instanceof IConfiguration){
+			IConfiguration cfg = (IConfiguration)context;
+			IConfigurationEnvironmentVariableSupplier supplier = cfg.getEnvironmentVariableSupplier();
+			if(supplier == null)
+				return null;
+			variables = supplier.getVariables(cfg,new ExtensionEnvVarProvider(context));
+		}
+		else if (context instanceof IManagedProject) {
+			IManagedProject project = (IManagedProject)context; 
+			IProjectEnvironmentVariableSupplier supplier = project.getProjectType().getEnvironmentVariableSupplier();
+			if(supplier == null)
+				return null;
+			variables = supplier.getVariables(project,new ExtensionEnvVarProvider(context));
+		}
+		
+		return filterVariables(variables);
+	}
+
+	protected IEnvironmentVariableSupplier[] filterValidSuppliers(IEnvironmentVariableSupplier suppliers[]){
+		if(suppliers == null)
+			return null;
+
+		int i = 0, j = 0;
+		for(i = 0; i < suppliers.length; i++){
+			if(suppliers[i] == this)
+				break;
+		}
+		
+	
+		if(i >= suppliers.length)
+			return null;
+		
+		int startNum = i + 1;
+
+
+		IEnvironmentVariableSupplier validSuppliers[] = 
+			new IEnvironmentVariableSupplier[suppliers.length - startNum];
+		
+		for(i = startNum, j = 0; i < suppliers.length; i++, j++)
+			validSuppliers[j] = suppliers[i];
+		
+		return validSuppliers;
+	}
+	
+	protected String getValidName(String name){
+		name = EnvVarOperationProcessor.normalizeName(name);
+		if(name == null)
+			return null;
+		if(fNonOverloadableVariables != null){
+			for(int i = 0; i < fNonOverloadableVariables.length; i++){
+				if(name.equals(fNonOverloadableVariables[i]))
+					return null;
+			}
+		}
+		return name;
+	}
+	
+	protected IBuildEnvironmentVariable[] filterVariables(IBuildEnvironmentVariable variables[]){
+		if(variables == null || variables.length == 0)
+			return variables;
+		
+		IBuildEnvironmentVariable filtered[] = new IBuildEnvironmentVariable[variables.length];
+		int filteredNum = 0;
+		for(int i = 0; i < variables.length; i++){
+			if(getValidName(variables[i].getName()) != null)
+				filtered[filteredNum++] = variables[i];
+		}
+
+		if(filteredNum != filtered.length){
+			IBuildEnvironmentVariable vars[] = new IBuildEnvironmentVariable[filteredNum];
+			for(int i = 0; i < filteredNum; i++)
+				vars[i] = filtered[i];
+			filtered = vars;
+		}
+		return filtered;
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/IContextInfo.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/IContextInfo.java
new file mode 100644
index 00000000000..c1ef2ad39f5
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/IContextInfo.java
@@ -0,0 +1,42 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+
+/**
+ * This interface is used by the Environment Variable Provider to
+ * represent the given context(level) information
+ * 
+ * @since 3.0
+ */
+public interface IContextInfo {
+	/**
+	 * Returns the next lower-precedence context
+	 * 
+	 * @return IContextInfo
+	 */
+	public IContextInfo getNext();
+
+	/**
+	 * Returns the array of suppliers to be used for this context
+	 * 
+	 * @return IEnvironmentVariableSupplier[]
+	 */
+	public IEnvironmentVariableSupplier[] getSuppliers();
+	
+	/**
+	 * Returns the current context
+	 * 
+	 * @return Object
+	 */
+	public Object getContext();
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/MbsEnvironmentSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/MbsEnvironmentSupplier.java
new file mode 100644
index 00000000000..caad9fc92d8
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/MbsEnvironmentSupplier.java
@@ -0,0 +1,90 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.cdt.managedbuilder.makegen.IManagedBuilderMakefileGenerator;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IResource;
+import org.eclipse.core.runtime.IPath;
+import org.eclipse.core.runtime.Path;
+
+/**
+ * This is the Environment Variable Supplier used to supply variables
+ * defined by the MBS
+ * 
+ * @since 3.0
+ */
+public class MbsEnvironmentSupplier implements IEnvironmentVariableSupplier {
+	private static final String fVariableNames[] = new String[]{
+		"CWD",	//$NON-NLS-1$
+		"PWD"	//$NON-NLS-1$
+	};
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariable()
+	 */
+	public IBuildEnvironmentVariable getVariable(String name, Object context) {
+		if(context instanceof IConfiguration)
+			return getConfigurationVariable(name,(IConfiguration)context);
+		return null;
+	}
+	
+	public IBuildEnvironmentVariable getConfigurationVariable(String name, IConfiguration configuration) {
+		IBuildEnvironmentVariable variable = null;
+		if("CWD".equals(name) || "PWD".equals(name)){	//$NON-NLS-1$	//$NON-NLS-2$
+			IResource owner = configuration.getOwner();
+			if(owner != null){
+				IManagedBuildInfo info = ManagedBuildManager.getBuildInfo(owner);
+				if(info != null && configuration.equals(info.getDefaultConfiguration())){
+					IManagedBuilderMakefileGenerator generator = ManagedBuildManager.getBuildfileGenerator(configuration);
+					generator.initialize((IProject)owner,info,null);
+					
+					IPath topBuildDir = generator.getBuildWorkingDir();
+					if(topBuildDir == null)
+						topBuildDir = new Path(info.getConfigurationName());
+
+					IPath projectLocation = owner.getLocation();
+					IPath workingDirectory = projectLocation.append(topBuildDir);
+					String value = workingDirectory.toOSString(); 
+					variable = new BuildEnvVar(name,value,IBuildEnvironmentVariable.ENVVAR_REPLACE,null);
+				}
+			}
+		}
+		return variable;
+	}
+	
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariables()
+	 */
+	public IBuildEnvironmentVariable[] getVariables(Object context) {
+		if(context instanceof IConfiguration){
+			List variables = new ArrayList(fVariableNames.length);
+			for(int i = 0; i < fVariableNames.length; i++){
+				IBuildEnvironmentVariable var = getConfigurationVariable(fVariableNames[i],(IConfiguration)context);
+				if(var != null)
+					variables.add(var);
+			}
+			if(variables.size() == 0)
+				return null;
+			return (IBuildEnvironmentVariable[])variables.toArray(new IBuildEnvironmentVariable[variables.size()]);
+		}
+		return null;
+	}
+
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvVar.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvVar.java
new file mode 100644
index 00000000000..f058b52742a
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvVar.java
@@ -0,0 +1,109 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+
+/**
+ * This class represents the Environment variable that could be loaded
+ * and stored in XML
+ * 
+ * @since 3.0
+ *
+ */
+public class StorableEnvVar extends BuildEnvVar {
+	public static final String VARIABLE_ELEMENT_NAME = "variable"; //$NON-NLS-1$
+	public static final String NAME = "name"; //$NON-NLS-1$
+	public static final String VALUE = "value"; //$NON-NLS-1$
+	public static final String OPERATION = "operation"; //$NON-NLS-1$
+	public static final String DELIMITER = "delimiter"; //$NON-NLS-1$
+	
+	public static final String REPLACE = "replace"; //$NON-NLS-1$
+	public static final String REMOVE = "remove"; //$NON-NLS-1$
+	public static final String APPEND = "append"; //$NON-NLS-1$
+	public static final String PREPEND = "prepend"; //$NON-NLS-1$
+	
+	public StorableEnvVar(String name, String value, int op, String delimiter){
+		super(name,value,op,delimiter);
+	}
+	
+	public StorableEnvVar(String name){
+		this(name,null,ENVVAR_REPLACE,null);
+	}
+	
+	public StorableEnvVar(String name, String value){
+		this(name,value,ENVVAR_REPLACE,null);	
+	}
+	
+	public StorableEnvVar(String name, String value, String delimiter){
+		this(name,value,ENVVAR_REPLACE,delimiter);	
+	}
+	
+	public StorableEnvVar(Element element){
+		load(element);
+	}
+	
+	private void load(Element element){
+		fName = element.getAttribute(NAME);
+
+		fValue = element.getAttribute(VALUE);
+
+		fOperation = opStringToInt(element.getAttribute(OPERATION));
+			
+		fDelimiter = element.getAttribute(DELIMITER);
+		if("".equals(fDelimiter))
+			fDelimiter = null;
+	}
+	
+	private int opStringToInt(String op){
+		int operation;
+		
+		if(REMOVE.equals(op))
+			operation = ENVVAR_REMOVE;
+		else if(APPEND.equals(op))
+			operation = ENVVAR_APPEND;
+		else if(PREPEND.equals(op))
+			operation = ENVVAR_PREPEND;
+		else
+			operation = ENVVAR_REPLACE;
+		
+		return operation;
+	}
+	
+	private String opIntToString(int op){
+		String operation;
+		
+		if(ENVVAR_REMOVE == op)
+			operation = REMOVE;
+		else if(ENVVAR_APPEND == op)
+			operation = APPEND;
+		else if(ENVVAR_PREPEND == op)
+			operation = PREPEND;
+		else
+			operation = REPLACE;
+		
+		return operation;
+	}
+
+	public void serialize(Document doc, Element element){
+		if(fName != null)
+			element.setAttribute(NAME,fName);
+		
+		if(fValue != null)
+			element.setAttribute(VALUE,fValue);
+		
+		element.setAttribute(OPERATION,opIntToString(fOperation));
+		
+		if(fDelimiter != null)
+			element.setAttribute(DELIMITER,fDelimiter);
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironment.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironment.java
new file mode 100644
index 00000000000..5c9119534c1
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironment.java
@@ -0,0 +1,195 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.Collection;
+import java.util.HashMap;
+import java.util.Iterator;
+import java.util.Map;
+
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableProvider;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * This class represents the set of environment variables that could be loaded
+ * and stored in XML
+ * 
+ * @since 3.0
+ *
+ */public class StorableEnvironment {
+	public static final String ENVIRONMENT_ELEMENT_NAME = "environment"; //$NON-NLS-1$
+	private Map fVariables;
+	private boolean fIsDirty = false;
+	private boolean fIsChanged = false;
+	
+	private Map getMap(){
+		if(fVariables == null)
+			fVariables = new HashMap();
+		return fVariables;
+	}
+	
+	public StorableEnvironment() {
+
+	}
+
+	public StorableEnvironment(Element element) {
+		load(element);
+	}
+	
+	private void load(Element element){
+		NodeList nodeList = element.getChildNodes();
+		for (int i = 0; i < nodeList.getLength(); ++i) {
+			Node node = nodeList.item(i);
+			if (node.getNodeName().equals(StorableEnvVar.VARIABLE_ELEMENT_NAME)) {
+				addVariable(new StorableEnvVar((Element)node));
+			}
+		}
+		fIsDirty = false;
+		fIsChanged = false;
+	}
+	
+	public void serialize(Document doc, Element element){
+		if(fVariables != null){
+			Iterator iter = fVariables.values().iterator();
+			while(iter.hasNext()){
+				StorableEnvVar var = (StorableEnvVar)iter.next();
+				Element varEl = doc.createElement(StorableEnvVar.VARIABLE_ELEMENT_NAME);
+				element.appendChild(varEl);
+				var.serialize(doc,varEl);
+			}
+		}
+		fIsDirty = false;
+	}
+
+	private void addVariable(IBuildEnvironmentVariable var){
+		String name = var.getName();
+		if(name == null)
+			return;
+		IEnvironmentVariableProvider provider = ManagedBuildManager.getEnvironmentVariableProvider();
+		if(!provider.isVariableCaseSensitive())
+			name = name.toUpperCase();
+		
+		getMap().put(name,var);
+	}
+
+	public IBuildEnvironmentVariable createVariable(String name, String value, int op, String delimiter){
+		if(name == null || "".equals(name = name.trim())) //$NON-NLS-1$
+			return null;
+
+		StorableEnvVar var = new StorableEnvVar(name, value, op, delimiter);
+		addVariable(var);
+		fIsDirty = true;
+		fIsChanged = true;
+		return var;
+	}
+
+	public IBuildEnvironmentVariable createVariable(String name){
+		return createVariable(name,null,IBuildEnvironmentVariable.ENVVAR_REPLACE,null);
+	}
+	
+	public IBuildEnvironmentVariable createVariable(String name, String value){
+		return createVariable(name,value,IBuildEnvironmentVariable.ENVVAR_REPLACE,null);	
+	}
+	
+	public IBuildEnvironmentVariable createVariable(String name, String value, String delimiter){
+		return createVariable(name,value,IBuildEnvironmentVariable.ENVVAR_REPLACE,delimiter);	
+	}
+	
+	/**
+	 * Returns the "dirty" state of the environment.
+	 * If the dirty state is <code>true</code>, that means that the environment 
+	 * is out of synch with the repository and the environment needs to be serialized.
+	 * <br><br>
+	 * The dirty state is automatically set to <code>false</code> when the environment is serialized
+	 * by calling the serialize() method  
+	 * @return boolean 
+	 */
+	public boolean isDirty(){
+		return fIsDirty;
+	}
+	
+	/**
+	 * sets the "dirty" state of the environment
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.StorableEnvironment#isDirty()
+	 * @param dirty represents the new state
+	 */
+	public void setDirty(boolean dirty){
+		fIsDirty = dirty;
+	}
+	
+	/**
+	 * Returns the "change" state of the environment.
+	 * The "change" state represents whether the environment was changed or not.
+	 * This state is not reset when the serialize() method is called
+	 * Users can use this state to monitor whether the environment was changed or not.
+	 * This state can be reset to <code>false</code> only by calling the setChanged(false) method 
+	 * @return boolean
+	 */
+	public boolean isChanged(){
+		return fIsChanged;
+	}
+	
+	/**
+	 * sets the "change" state of the environment
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.StorableEnvironment#isChanged()
+	 * @param changed represents the new "change" state
+	 */
+	public void setChanged(boolean changed){
+		fIsChanged = changed;
+	}
+
+	public IBuildEnvironmentVariable getVariable(String name){
+		if(name == null || "".equals(name = name.trim())) //$NON-NLS-1$
+			return null;
+		IEnvironmentVariableProvider provider = EnvironmentVariableProvider.getDefault();
+		if(!provider.isVariableCaseSensitive())
+			name = name.toUpperCase();
+		
+		return (IBuildEnvironmentVariable)getMap().get(name);
+	}
+	
+	public IBuildEnvironmentVariable[] getVariables(){
+		Collection vars = getMap().values();
+		
+		return (IBuildEnvironmentVariable[])vars.toArray(new IBuildEnvironmentVariable[vars.size()]);
+	}
+	
+	IBuildEnvironmentVariable deleteVariable(String name){
+		if(name == null || "".equals(name = name.trim())) //$NON-NLS-1$
+			return null;
+		IEnvironmentVariableProvider provider = ManagedBuildManager.getEnvironmentVariableProvider();
+		if(!provider.isVariableCaseSensitive())
+			name = name.toUpperCase();
+
+		IBuildEnvironmentVariable var = (IBuildEnvironmentVariable)getMap().remove(name);
+		if(var != null){
+			fIsDirty = true;
+			fIsChanged = true;
+		}
+
+		return var;
+	}
+	
+	public void deleteAll(){
+		Map map = getMap();
+		if(map.size() > 0){
+			fIsDirty = true;
+			fIsChanged = true;
+		}
+		
+		map.clear();
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironmentLoader.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironmentLoader.java
new file mode 100644
index 00000000000..a63b37e6958
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StorableEnvironmentLoader.java
@@ -0,0 +1,220 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+
+import javax.xml.parsers.DocumentBuilder;
+import javax.xml.parsers.DocumentBuilderFactory;
+import javax.xml.parsers.ParserConfigurationException;
+import javax.xml.transform.OutputKeys;
+import javax.xml.transform.Transformer;
+import javax.xml.transform.TransformerConfigurationException;
+import javax.xml.transform.TransformerException;
+import javax.xml.transform.TransformerFactory;
+import javax.xml.transform.dom.DOMSource;
+import javax.xml.transform.stream.StreamResult;
+
+import org.eclipse.cdt.managedbuilder.core.ManagedBuilderCorePlugin;
+import org.eclipse.cdt.managedbuilder.internal.core.ManagedMakeMessages;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.IStatus;
+import org.eclipse.core.runtime.Status;
+import org.osgi.service.prefs.BackingStoreException;
+import org.osgi.service.prefs.Preferences;
+import org.w3c.dom.Document;
+import org.w3c.dom.Element;
+import org.xml.sax.InputSource;
+import org.xml.sax.SAXException;
+
+/**
+ * This class implements the common functionality that allows
+ * storing and loading environment variable settings from eclipse properties
+ * 
+ * @since 3.0
+ *
+ */
+public abstract class StorableEnvironmentLoader {
+
+	/**
+	 * this interface represents the preference node and the preference name
+	 * that are used for holding the environment data 
+	 * 
+	 */
+	protected interface ISerializeInfo{
+		Preferences getNode();
+		
+		String getPrefName();
+	}
+
+	/**
+	 * this method should return the ISerializeInfo representing the information
+	 * of where the variable should be stored and loaded
+	 * If the given context is not supported this method should return null
+	 * 
+	 * @param context
+	 * @return
+	 */
+	protected abstract ISerializeInfo getSerializeInfo(Object context);
+
+	/*
+	 * loads the stored environment for the given context 
+	 */
+	protected StorableEnvironment loadEnvironment(Object context){
+		ISerializeInfo serializeInfo = getSerializeInfo(context);
+		if(serializeInfo == null)
+			return null;
+		
+		InputStream stream = loadInputStream(serializeInfo.getNode(),serializeInfo.getPrefName());
+		if(stream == null)
+			return new StorableEnvironment();
+		return loadEnvironmentFromStream(stream);
+	}
+	
+	/*
+	 * stores the given environment 
+	 */
+	protected void storeEnvironment(StorableEnvironment env, Object context, boolean force) throws CoreException{
+		if(!env.isDirty() && !force)
+			return;
+		
+		ISerializeInfo serializeInfo = getSerializeInfo(context);
+		if(serializeInfo == null)
+			return;
+		
+		ByteArrayOutputStream stream = storeEnvironmentToStream(env);
+		if(stream == null)
+			return;
+		storeOutputStream(stream,serializeInfo.getNode(),serializeInfo.getPrefName());
+	}
+	
+	private StorableEnvironment loadEnvironmentFromStream(InputStream stream){
+		try{
+			DocumentBuilder parser = DocumentBuilderFactory.newInstance().newDocumentBuilder();
+			InputSource inputSource = new InputSource(stream);
+			Document document = parser.parse(inputSource);
+			Element rootElement = document.getDocumentElement();
+			
+			if(!StorableEnvironment.ENVIRONMENT_ELEMENT_NAME.equals(rootElement.getNodeName()))
+				return null;
+			
+			return new StorableEnvironment(rootElement);
+		}
+		catch(ParserConfigurationException e){
+			
+		}
+		catch(SAXException e){
+			
+		}
+		catch(IOException e){
+			
+		}
+		
+		return null;
+	}
+	
+	private ByteArrayOutputStream storeEnvironmentToStream(StorableEnvironment env) throws CoreException{
+		try{
+			DocumentBuilderFactory factory= DocumentBuilderFactory.newInstance();
+			DocumentBuilder builder= factory.newDocumentBuilder();		
+			Document document= builder.newDocument();
+			
+			Element rootElement = document.createElement(StorableEnvironment.ENVIRONMENT_ELEMENT_NAME);
+			document.appendChild(rootElement);
+			env.serialize(document,rootElement);
+			
+			Transformer transformer=TransformerFactory.newInstance().newTransformer();
+			transformer.setOutputProperty(OutputKeys.METHOD, "xml"); //$NON-NLS-1$
+			transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8"); //$NON-NLS-1$
+			transformer.setOutputProperty(OutputKeys.INDENT, "yes"); //$NON-NLS-1$
+			DOMSource source = new DOMSource(document);
+			
+			ByteArrayOutputStream stream = new ByteArrayOutputStream();
+			StreamResult result = new StreamResult(stream);
+	
+			transformer.transform(source, result);
+			return stream;
+		}
+		catch(ParserConfigurationException e){
+			throw new CoreException(new Status(IStatus.ERROR, 
+					ManagedBuilderCorePlugin.getUniqueIdentifier(),
+					-1,
+					e.getMessage(),
+					e));
+		}
+		catch(TransformerConfigurationException e){
+			throw new CoreException(new Status(IStatus.ERROR, 
+					ManagedBuilderCorePlugin.getUniqueIdentifier(),
+					-1,
+					e.getMessage(),
+					e));
+		}
+		catch(TransformerException e){
+			throw new CoreException(new Status(IStatus.ERROR, 
+					ManagedBuilderCorePlugin.getUniqueIdentifier(),
+					-1,
+					e.getMessage(),
+					e));
+		}
+	}
+	
+	private InputStream loadInputStream(Preferences node, String key){
+		if(node == null || key == null)
+			return null;
+		
+		String value = node.get(key,null);
+		if(value == null || value.length() == 0)
+			return null;
+		
+		byte[] bytes;
+		try {
+			bytes = value.getBytes("UTF-8"); //$NON-NLS-1$
+		} catch (UnsupportedEncodingException e) {
+			bytes = value.getBytes();
+		}
+		
+		return new ByteArrayInputStream(bytes);
+	}
+	
+	private void storeOutputStream(ByteArrayOutputStream stream, Preferences node, String key) throws CoreException{
+		if(stream == null || node == null || key == null)
+			throw new CoreException(new Status(IStatus.ERROR, 
+					ManagedBuilderCorePlugin.getUniqueIdentifier(),
+					-1,
+					ManagedMakeMessages.getResourceString("StorableEnvironmentLoader.storeOutputStream.wrong.arguments"), //$NON-NLS-1$
+					null));
+		byte[] bytes= stream.toByteArray();
+		
+		String val = null;
+		try {
+			val= new String(bytes, "UTF-8"); //$NON-NLS-1$
+		} catch (UnsupportedEncodingException e) {
+			val= new String(bytes);
+		}
+		
+		node.put(key,val);
+		
+		try{
+			node.flush();
+		}
+		catch(BackingStoreException e){
+			throw new CoreException(new Status(IStatus.ERROR, 
+					ManagedBuilderCorePlugin.getUniqueIdentifier(),
+					-1,
+					e.getMessage(),
+					e));
+		}
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StoredBuildPathEnvironmentContainer.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StoredBuildPathEnvironmentContainer.java
new file mode 100644
index 00000000000..5e7fb69bd8a
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/StoredBuildPathEnvironmentContainer.java
@@ -0,0 +1,265 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.List;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IEnvVarBuildPath;
+import org.eclipse.cdt.managedbuilder.core.ITool;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuilderCorePlugin;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.ProjectScope;
+import org.eclipse.core.runtime.CoreException;
+import org.osgi.service.prefs.Preferences;
+
+/**
+ * This class holds the build path variable values and allows
+ * checking the stored variable values with the values of the current environment environment
+ * 
+ * @since 3.0
+ *
+ */
+public class StoredBuildPathEnvironmentContainer extends
+		StorableEnvironmentLoader {
+	public static final String NODENAME = "environment";   //$NON-NLS-1$
+	public static final String NODENAME_PREFIX_CFG = "buildEnvironment";  //$NON-NLS-1$
+	public static final String NODENAME_CFG_INCLUDE = NODENAME_PREFIX_CFG + "Include";  //$NON-NLS-1$
+	public static final String NODENAME_CFG_LIBRARY = NODENAME_PREFIX_CFG + "Library";  //$NON-NLS-1$
+	
+	private IConfiguration fConfiguration;
+	private StorableEnvironment fEnvironment;
+	private int fPathType;
+	private boolean fIsVariableCaseSensitive = ManagedBuildManager.getEnvironmentVariableProvider().isVariableCaseSensitive();
+
+	public StoredBuildPathEnvironmentContainer(int pathType){
+		fPathType = pathType == IEnvVarBuildPath.BUILDPATH_LIBRARY ? 
+				IEnvVarBuildPath.BUILDPATH_LIBRARY : IEnvVarBuildPath.BUILDPATH_INCLUDE;
+	}
+
+	protected StorableEnvironment getEnvironment(Object context) {
+		StorableEnvironment env = null;
+		if(context instanceof IConfiguration){
+			if(fConfiguration != null && context == fConfiguration && fEnvironment != null)
+				env = fEnvironment;
+			else {
+				env = loadEnvironment(context);
+				if(env != null){
+					if(fConfiguration != null && fEnvironment != null){
+						try{
+							storeEnvironment(fEnvironment,fConfiguration,false);
+						}catch(CoreException e){
+						}
+					}
+
+					checkLoadedVarNames(env,context);
+					
+					fConfiguration = (IConfiguration)context;
+					fEnvironment = env;
+				}
+			}
+		}
+		return env;
+	}
+	
+	private boolean haveIdenticalValues(IBuildEnvironmentVariable var1,
+			IBuildEnvironmentVariable var2){
+		if(var1 == null)
+			return var2 == null || var2.getOperation() == IBuildEnvironmentVariable.ENVVAR_REMOVE;
+		if(var2 == null)
+			return var1 == null || var1.getOperation() == IBuildEnvironmentVariable.ENVVAR_REMOVE;
+		int op1 = var1.getOperation(); 
+		int op2 = var2.getOperation();
+		if(op1 == IBuildEnvironmentVariable.ENVVAR_REMOVE ||
+				op2 == IBuildEnvironmentVariable.ENVVAR_REMOVE)
+			return op1 == op2;
+		
+		return maskNull(var1.getValue()).equals(maskNull(var2.getValue()));
+	}
+
+	private String maskNull(String val){
+		return val == null ? "" : val;  //$NON-NLS-1$
+	}
+
+	public boolean checkBuildPathChange(EnvVarCollector existingVariables, 
+			IConfiguration configuration){
+		StorableEnvironment env = getEnvironment(configuration);
+		if(env == null)
+			return false;
+		IBuildEnvironmentVariable vars[] = env.getVariables();
+		for(int i = 0; i < vars.length; i++){
+			IBuildEnvironmentVariable var = vars[i];
+			String name = var.getName();
+			IBuildEnvironmentVariable curVar = existingVariables != null ? 
+					existingVariables.getVariable(name) : null;
+			if(!haveIdenticalValues(var,curVar)){
+				if(curVar == null){
+					env.createVariable(name,null,IBuildEnvironmentVariable.ENVVAR_REMOVE,null);
+				}
+				else{
+					env.createVariable(curVar.getName(),curVar.getValue(),curVar.getOperation(),curVar.getDelimiter());
+				}
+			}
+		}
+		boolean changed = env.isChanged();
+		env.setChanged(false);
+		if(changed)
+			try{
+				storeEnvironment(env,configuration,false);
+			}catch(CoreException e){
+			}
+		return changed;
+	}
+	
+	/*
+	 * checks whether the variable of a given name is the build path variable
+	 * for the given configuration
+	 * If it is, than performs a check and returns true if the variable was changed
+	 * If it is not the build path variable, no check is performed and this method always
+	 * returns false in this case
+	 */
+	public boolean isVariableChanged(String name, 
+			IBuildEnvironmentVariable variable, 
+			IConfiguration configuration){
+		StorableEnvironment env = getEnvironment(configuration);
+		if(env == null)
+			return false;
+		IBuildEnvironmentVariable var = env.getVariable(name);
+		if(var == null)
+			return false;
+		
+		if(haveIdenticalValues(var,variable))
+			return false;
+
+		return true;
+	}
+	
+	/*
+	 * synchronizes the stored variables with the ones passed to this method 
+	 */
+	public void synchronize(EnvVarCollector existingVariables,
+			IConfiguration configuration){
+		checkBuildPathChange(existingVariables,configuration);
+	}
+	
+	private void checkLoadedVarNames(StorableEnvironment env, Object context){
+		String varNames[] = getBuildPathVarNames((IConfiguration)context, fPathType);
+		for(int i = 0; i < varNames.length; i++){
+			String name = varNames[i];
+			if(env.getVariable(name) == null)
+				env.createVariable(name,null,IBuildEnvironmentVariable.ENVVAR_REMOVE,null);
+		}
+
+		IBuildEnvironmentVariable vars[] = env.getVariables();
+		for(int i = 0; i < vars.length; i++){
+			IBuildEnvironmentVariable var = vars[i];
+			boolean validVar = false;
+			for(int j = 0; j < varNames.length; j++){
+				String varName = varNames[j]; 
+				if(varNamesEqual(var.getName(),varName)){
+					validVar = true;
+					break;
+				}
+			}
+			if(!validVar){
+				env.deleteVariable(var.getName());
+			}
+		}
+	}
+	
+	/*
+	 * returns true if the variable names are equal and false otherwise
+	 */
+	private boolean varNamesEqual(String name1, String name2){
+		return fIsVariableCaseSensitive ?
+				name1.equals(name2) : name1.equalsIgnoreCase(name2);
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.internal.envvar.StorableEnvironmentLoader#getSerializeInfo(java.lang.Object)
+	 */
+	protected ISerializeInfo getSerializeInfo(Object context) {
+		ISerializeInfo serializeInfo = null;
+		if(context instanceof IConfiguration){
+			IConfiguration cfg = (IConfiguration)context;
+			final Preferences prefs = getConfigurationNode(cfg);
+			final String name = cfg.getId();
+			if(prefs != null && name != null)
+				serializeInfo = new ISerializeInfo(){
+				public Preferences getNode(){
+					return prefs;
+				}
+				
+				public String getPrefName(){
+					return name;
+				}
+			};
+		}
+		return serializeInfo;
+	}
+
+	public void serialize(boolean force) {
+		if(fEnvironment != null){
+			try{
+				storeEnvironment(fEnvironment,fConfiguration,force);
+			}catch(CoreException e){
+			}
+		}
+	}
+	
+	private Preferences getConfigurationNode(IConfiguration cfg){
+		IProject project = (IProject)cfg.getOwner();
+		if(project == null || !project.exists())
+			return null;
+		
+		Preferences prefNode = new ProjectScope(project).getNode(ManagedBuilderCorePlugin.getUniqueIdentifier());
+		if(prefNode == null)
+			return null;
+		
+		prefNode = prefNode.node(NODENAME);
+		if(prefNode == null)
+			return null;
+		
+		if(fPathType == IEnvVarBuildPath.BUILDPATH_LIBRARY)
+			return prefNode.node(NODENAME_CFG_LIBRARY);
+		return prefNode.node(NODENAME_CFG_INCLUDE);
+	}
+	
+	private String[] getBuildPathVarNames(IConfiguration configuration,int buildPathType){
+		ITool tools[] = configuration.getFilteredTools();
+		List list = new ArrayList();
+		
+		for(int i = 0; i < tools.length; i++){
+			IEnvVarBuildPath pathDescriptors[] = tools[i].getEnvVarBuildPaths();
+			
+			if(pathDescriptors == null || pathDescriptors.length == 0)
+				continue;
+			
+			for(int j = 0; j < pathDescriptors.length; j++){
+				IEnvVarBuildPath curPathDes = pathDescriptors[j];
+				if(curPathDes.getType() != buildPathType)
+					continue;
+				
+				String vars[] = curPathDes.getVariableNames();
+				if(vars == null || vars.length == 0)
+					continue;
+				
+				list.addAll(Arrays.asList(vars));
+			}
+		}
+		
+		return (String[])list.toArray(new String[list.size()]);
+	}
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/UserDefinedEnvironmentSupplier.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/UserDefinedEnvironmentSupplier.java
new file mode 100644
index 00000000000..92d8c54b1c2
--- /dev/null
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/internal/envvar/UserDefinedEnvironmentSupplier.java
@@ -0,0 +1,349 @@
+/**********************************************************************
+ * Copyright (c) 2005 Intel Corporation and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Common Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/cpl-v10.html
+ * 
+ * Contributors: 
+ * Intel Corporation - Initial API and implementation
+ **********************************************************************/
+package org.eclipse.cdt.managedbuilder.internal.envvar;
+
+import org.eclipse.cdt.managedbuilder.core.IConfiguration;
+import org.eclipse.cdt.managedbuilder.core.IManagedBuildInfo;
+import org.eclipse.cdt.managedbuilder.core.IManagedProject;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuildManager;
+import org.eclipse.cdt.managedbuilder.core.ManagedBuilderCorePlugin;
+import org.eclipse.cdt.managedbuilder.envvar.IBuildEnvironmentVariable;
+import org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier;
+import org.eclipse.core.resources.IProject;
+import org.eclipse.core.resources.IWorkspace;
+import org.eclipse.core.resources.ProjectScope;
+import org.eclipse.core.resources.ResourcesPlugin;
+import org.eclipse.core.runtime.CoreException;
+import org.eclipse.core.runtime.preferences.InstanceScope;
+import org.osgi.service.prefs.BackingStoreException;
+import org.osgi.service.prefs.Preferences;
+
+/**
+ * This is the Environment Variable Supplier used to supply variables
+ * defined by a user
+ * 
+ * @since 3.0
+ */
+public class UserDefinedEnvironmentSupplier extends 
+			StorableEnvironmentLoader 
+			implements IEnvironmentVariableSupplier{
+
+	public static final String NODENAME = "environment";  //$NON-NLS-1$
+	public static final String PREFNAME_WORKSPACE = "workspace";  //$NON-NLS-1$
+	public static final String PREFNAME_PROJECT = "project";  //$NON-NLS-1$
+	public static final String NODENAME_CFG = "project";  //$NON-NLS-1$
+
+	private static final String fNonOverloadableVariables[] = new String[]{
+			//users not allowed currently to override the "CWD" and "PWD" variables
+			EnvVarOperationProcessor.normalizeName("CWD"),   //$NON-NLS-1$
+			EnvVarOperationProcessor.normalizeName("PWD")	  //$NON-NLS-1$
+		};
+
+	private StorableEnvironment fConfigurationVariables;
+	private StorableEnvironment fProjectVariables;
+	private StorableEnvironment fWorkspaceVariables;
+	
+	private IConfiguration fCurrentCfg = null;
+	private IManagedProject fCurrentProj = null;
+
+	protected StorableEnvironment getEnvironment(Object context){
+		if(context == null)
+			return null;
+		
+		StorableEnvironment env = null;
+		if(context instanceof IConfiguration){
+			IConfiguration newCfg = (IConfiguration)context;
+			if(fCurrentCfg == newCfg && fConfigurationVariables != null){
+				env = fConfigurationVariables;
+			}
+			else{
+				env = loadEnvironment(newCfg);
+				if(env != null){
+					if(fConfigurationVariables != null)
+						try{
+							storeEnvironment(fConfigurationVariables,fCurrentCfg,false);
+						} catch(CoreException e){
+						}
+					fConfigurationVariables = env;
+					fCurrentCfg = newCfg;
+				}
+			}
+		}
+		else if(context instanceof IManagedProject){
+			IManagedProject newProj = (IManagedProject)context;
+			if(fCurrentProj == newProj && fProjectVariables != null){
+				env = fProjectVariables;
+			}
+			else{
+				env = loadEnvironment(newProj);
+				if(env != null){
+					if(fProjectVariables != null)
+						try{
+							storeEnvironment(fProjectVariables,fCurrentProj,false);
+						} catch(CoreException e){
+						}
+						fProjectVariables = env; 
+						fCurrentProj = newProj;
+				}
+			}
+		}
+		else if(context instanceof IWorkspace){
+			if(fWorkspaceVariables == null)
+				fWorkspaceVariables = loadEnvironment(context);
+			env = fWorkspaceVariables;
+		}
+		
+		return env;
+	}
+	
+	protected ISerializeInfo getSerializeInfo(Object context){
+		ISerializeInfo serializeInfo = null;
+		
+		if(context instanceof IConfiguration){
+			IConfiguration cfg = (IConfiguration)context;
+			IManagedProject project = cfg.getManagedProject();
+			
+			final Preferences prefs = project != null ? getConfigurationNode(project) : null;
+			final String name = cfg.getId();
+			if(prefs != null && name != null)
+				serializeInfo = new ISerializeInfo(){
+				public Preferences getNode(){
+					return prefs;
+				}
+				
+				public String getPrefName(){
+					return name;
+				}
+			};
+		}
+		else if(context instanceof IManagedProject){
+			IManagedProject proj = (IManagedProject)context;
+			final Preferences prefs = getProjectNode(proj);
+			final String name = PREFNAME_PROJECT;
+			if(prefs != null && name != null)
+				serializeInfo = new ISerializeInfo(){
+				public Preferences getNode(){
+					return prefs;
+				}
+				
+				public String getPrefName(){
+					return name;
+				}
+			};
+		}
+		else if(context instanceof IWorkspace){
+			final Preferences prefs = getWorkspaceNode();
+			final String name = PREFNAME_WORKSPACE;
+			if(prefs != null && name != null)
+				serializeInfo = new ISerializeInfo(){
+				public Preferences getNode(){
+					return prefs;
+				}
+				
+				public String getPrefName(){
+					return name;
+				}
+			};
+		}
+		return serializeInfo;
+	}
+	private Preferences getConfigurationNode(IManagedProject managedProject){
+		Preferences prefNode = getProjectNode(managedProject);
+		if(prefNode == null)
+			return null;
+		
+		return prefNode.node(NODENAME_CFG);
+	}
+	
+	private Preferences getProjectNode(IManagedProject managedProject){
+		IProject project = (IProject)managedProject.getOwner();
+		if(!project.exists())
+			return null;
+		
+		Preferences prefNode = new ProjectScope(project).getNode(ManagedBuilderCorePlugin.getUniqueIdentifier());
+		if(prefNode == null)
+			return null;
+		
+		return prefNode.node(NODENAME);
+	}
+	
+	private Preferences getWorkspaceNode(){
+		Preferences prefNode = new InstanceScope().getNode(ManagedBuilderCorePlugin.getUniqueIdentifier());
+		if(prefNode == null)
+			return null;
+		
+		return prefNode.node(NODENAME);
+	}
+	
+	public void checkInexistentConfigurations(IManagedProject managedProject){
+		Preferences prefNode = getConfigurationNode(managedProject);
+		if(prefNode == null)
+			return;
+		
+		try{
+			String ids[] = prefNode.childrenNames();
+			boolean found = false;
+			for( int i = 0; i < ids.length; i++){
+				if(managedProject.getConfiguration(ids[i]) == null){
+					prefNode.remove(ids[i]);
+					found = true;
+				}
+			}
+			
+			if(found)
+				prefNode.flush();
+		}
+		catch(BackingStoreException e){
+		}
+	}
+	
+	public void serialize(boolean force){
+		if(fConfigurationVariables != null && fCurrentCfg != null ){
+			try{
+				storeEnvironment(fConfigurationVariables,fCurrentCfg,force);
+			} catch(CoreException e){
+				
+			}
+		}
+
+		if(fProjectVariables != null && fCurrentProj != null ){
+			try{
+				storeEnvironment(fProjectVariables,fCurrentProj,force);
+			} catch(CoreException e){
+				
+			}
+		}
+		
+		if(fWorkspaceVariables != null){
+			try{
+				storeEnvironment(fWorkspaceVariables,ResourcesPlugin.getWorkspace(),force);
+			} catch(CoreException e){
+				
+			}
+
+		}
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariable()
+	 */
+	public IBuildEnvironmentVariable getVariable(String name, Object context) {
+		if(getValidName(name) == null)
+			return null;
+		StorableEnvironment env = getEnvironment(context);
+		if(env == null)
+			return null;
+		return env.getVariable(name);
+	}
+
+	/* (non-Javadoc)
+	 * @see org.eclipse.cdt.managedbuilder.envvar.IEnvironmentVariableSupplier#getVariables()
+	 */
+	public IBuildEnvironmentVariable[] getVariables(Object context) {
+		StorableEnvironment env = getEnvironment(context);
+		if(env == null)
+			return null;
+		return filterVariables(env.getVariables());
+	}
+	
+	public IBuildEnvironmentVariable createVariable(String name, String value, int op, String delimiter, Object context){
+		if(getValidName(name) == null)
+			return null;
+		StorableEnvironment env = getEnvironment(context);
+		if(env == null)
+			return null;
+		IBuildEnvironmentVariable var =  env.createVariable(name,value,op,delimiter);
+		setRebuildStateForContext(context);
+		return var;
+	}
+
+	public IBuildEnvironmentVariable deleteVariable(String name, Object context){
+		StorableEnvironment env = getEnvironment(context);
+		if(env == null)
+			return null;
+		IBuildEnvironmentVariable var = env.deleteVariable(name);
+		if(var != null)
+			setRebuildStateForContext(context);
+		return var;
+	}
+	
+	public void deleteAll(Object context){
+		StorableEnvironment env = getEnvironment(context);
+		if(env == null)
+			return;
+
+		env.deleteAll();
+		setRebuildStateForContext(context);
+	}
+	
+	protected void setRebuildStateForContext(Object context){
+		if(context == null)
+			return;
+		if(context instanceof IConfiguration){
+			((IConfiguration)context).setRebuildState(true);
+		}
+		else if(context instanceof IManagedProject){
+			IConfiguration cfgs[] = ((IManagedProject)context).getConfigurations();
+			for(int i = 0; i < cfgs.length; i++){
+				cfgs[i].setRebuildState(true);
+			}
+		}
+		else if(context instanceof IWorkspace){
+			IProject projects[] = ((IWorkspace)context).getRoot().getProjects();
+			for(int i = 0; i < projects.length; i++){
+				if(ManagedBuildManager.manages(projects[i])){
+					IManagedBuildInfo info = ManagedBuildManager.getBuildInfo(projects[i]);
+					if(info != null){
+						IConfiguration cfgs[] = info.getManagedProject().getConfigurations();
+						for(int j = 0; j < cfgs.length; j++){
+							cfgs[j].setRebuildState(true);
+						}
+					}
+				}
+			}
+		}
+			
+	}
+
+	protected String getValidName(String name){
+		name = EnvVarOperationProcessor.normalizeName(name);
+		if(name == null)
+			return null;
+		if(fNonOverloadableVariables != null){
+			for(int i = 0; i < fNonOverloadableVariables.length; i++){
+				if(name.equals(fNonOverloadableVariables[i]))
+					return null;
+			}
+		}
+		return name;
+	}
+	
+	protected IBuildEnvironmentVariable[] filterVariables(IBuildEnvironmentVariable variables[]){
+		if(variables == null || variables.length == 0)
+			return variables;
+		
+		IBuildEnvironmentVariable filtered[] = new IBuildEnvironmentVariable[variables.length];
+		int filteredNum = 0;
+		for(int i = 0; i < variables.length; i++){
+			if(getValidName(variables[i].getName()) != null)
+				filtered[filteredNum++] = variables[i];
+		}
+
+		if(filteredNum != filtered.length){
+			IBuildEnvironmentVariable vars[] = new IBuildEnvironmentVariable[filteredNum];
+			for(int i = 0; i < filteredNum; i++)
+				vars[i] = filtered[i];
+			filtered = vars;
+		}
+		return filtered;
+	}
+
+}
diff --git a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/GnuMakefileGenerator.java b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/GnuMakefileGenerator.java
index cbc09e5f59d..2d8175b8dbd 100644
--- a/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/GnuMakefileGenerator.java
+++ b/build/org.eclipse.cdt.managedbuilder.core/src/org/eclipse/cdt/managedbuilder/makegen/gnu/GnuMakefileGenerator.java
@@ -311,6 +311,8 @@ public class GnuMakefileGenerator implements IManagedBuilderMakefileGenerator {
 		for (int i=0; i<buildTools.length; i++) buildToolsUsed[i] = false;
 		// Initialize the tool info array
 		gnuToolInfos = new ManagedBuildGnuToolInfo[buildTools.length];
+		//set the top build dir path
+		topBuildDir = project.getFolder(info.getConfigurationName()).getFullPath();
 	}
 
 	/* (non-Javadoc)