1. Schema fixes

2. test tool-chain definition fixes

build/org.eclipse.cdt.managedbuilder.core.tests/plugin.xml

@@ -7781,8 +7781,7 @@
           superClass="test.four.dot.zero.cdt.managedbuild.tool.gnu.c.linker">
           <envVarBuildPath 
               pathType="buildpathLibrary"
-              variableList="LIBRARY_PATH"
-              buildPathResolver="org.eclipse.cdt.managedbuilder.gnu.cygwin.CygwinPathResolver">
+              variableList="LIBRARY_PATH">
           </envVarBuildPath>
           <outputType
 			  outputs="exe"
@@ -7804,8 +7803,7 @@
           superClass="test.four.dot.zero.cdt.managedbuild.tool.gnu.cpp.linker">
           <envVarBuildPath 
               pathType="buildpathLibrary"
-              variableList="LIBRARY_PATH"
-              buildPathResolver="org.eclipse.cdt.managedbuilder.gnu.cygwin.CygwinPathResolver">
+              variableList="LIBRARY_PATH">
           </envVarBuildPath>
 		  <outputType
 			  outputs="exe"
@@ -7824,13 +7822,12 @@
       <tool
           id="test.four.dot.zero.cdt.managedbuild.tool.gnu.c.compiler.cygwin"
           name="Test 4.0 ToolName.compiler.cygwin.gnu.c"
-          isTest="true"
+          isSystem="true"
           superClass="test.four.dot.zero.cdt.managedbuild.tool.gnu.c.compiler"
           optionPathConverter="org.eclipse.cdt.managedbuilder.core.tests.OneDirectionalPathConverter">
           <envVarBuildPath 
               pathType="buildpathInclude"
-              variableList="CPATH,C_INCLUDE_PATH"
-              buildPathResolver="org.eclipse.cdt.managedbuilder.gnu.cygwin.CygwinPathResolver">
+              variableList="CPATH,C_INCLUDE_PATH">
           </envVarBuildPath>
           <inputType
           	  id="test.four.dot.zero.cdt.managedbuild.tool.gnu.c.compiler.input.cygwin"
@@ -7844,8 +7841,7 @@
           optionPathConverter="org.eclipse.cdt.managedbuilder.core.tests.BidirectionalPathConverter">
           <envVarBuildPath 
               pathType="buildpathInclude"
-              variableList="CPATH,CPLUS_INCLUDE_PATH"
-              buildPathResolver="org.eclipse.cdt.managedbuilder.gnu.cygwin.CygwinPathResolver">
+              variableList="CPATH,CPLUS_INCLUDE_PATH">
           </envVarBuildPath>
           <inputType
           	  id="test.four.dot.zero.cdt.managedbuild.tool.gnu.cpp.compiler.input.cygwin"

build/org.eclipse.cdt.managedbuilder.core/schema/buildDefinitions.exsd

@@ -485,6 +485,13 @@ The pathConverter of a toolchain applies for all tools of the toolchain except i
                </documentation>
             </annotation>
          </attribute>
+         <attribute name="isSystem" type="boolean">
+            <annotation>
+               <documentation>
+                  the system elements are used by the system for specific needs and are not displayed in UI
+               </documentation>
+            </annotation>
+         </attribute>
       </complexType>
    </element>
 
@@ -772,6 +779,13 @@ The pathConverter of a toolchain applies for all tools of the toolchain except i
                </documentation>
             </annotation>
          </attribute>
+         <attribute name="isSystem" type="boolean">
+            <annotation>
+               <documentation>
+                  the system elements are used by the system for specific needs and are not displayed in UI
+               </documentation>
+            </annotation>
+         </attribute>
       </complexType>
    </element>
 
@@ -1675,6 +1689,13 @@ If the builder supports specifying custom number of parallel jobs, the option de
                </documentation>
             </annotation>
          </attribute>
+         <attribute name="isSystem" type="boolean">
+            <annotation>
+               <documentation>
+                  the system elements are used by the system for specific needs and are not displayed in UI
+               </documentation>
+            </annotation>
+         </attribute>
       </complexType>
    </element>
 

core/org.eclipse.cdt.core/schema/projectConverter.exsd

@@ -12,6 +12,9 @@
 
    <element name="extension">
       <complexType>
+         <sequence>
+            <element ref="converter"/>
+         </sequence>
          <attribute name="point" type="string" use="required">
             <annotation>
                <documentation>
@@ -39,6 +42,35 @@
       </complexType>
    </element>
 
+   <element name="converter">
+      <complexType>
+         <attribute name="owners" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+            </annotation>
+         </attribute>
+         <attribute name="natures" type="string">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+            </annotation>
+         </attribute>
+         <attribute name="class" type="string" use="required">
+            <annotation>
+               <documentation>
+                  
+               </documentation>
+               <appInfo>
+                  <meta.attribute kind="java" basedOn="org.eclipse.cdt.core.settings.model.extension.ICProjectConverter"/>
+               </appInfo>
+            </annotation>
+         </attribute>
+      </complexType>
+   </element>
+
    <annotation>
       <appInfo>
          <meta.section type="since"/>