Define the open declaration action properly

build/org.eclipse.cdt.make.ui/plugin.properties

@@ -45,6 +45,9 @@ ViewMake.name=Make Targets
 ActionSetMake.label=Make Actions
 ActionSetUpdateMake.label=Update Make Projects
 
+# Scope and Key Commands 
+scope.makefileEditor.name=Makefile Editor
+makefileEditor.description=Editor for makefiles
                                                                                                                              
 category.source.name=Makefile Source
 category.source.description= Makefile Source Actions
@@ -54,6 +57,9 @@ ActionDefinition.comment.description= Turn the selected lines into # style comme
  
 ActionDefinition.uncomment.name= Uncomment
 ActionDefinition.uncomment.description= Uncomment the selected # style comment lines
+
+ActionDefinition.opendecl.name= Open declation
+ActionDefinition.opendecl.description=Follow to the directive definition
  
 MakefileEditor.name=Makefile Editor
 

build/org.eclipse.cdt.make.ui/plugin.xml

@@ -225,7 +225,13 @@
       </objectContribution>
    </extension>
    <extension
-         point="org.eclipse.ui.commands">
+      point="org.eclipse.ui.commands">
+      <scope
+            name="%scope.makefileEditor.name"
+            parent="org.eclipse.ui.textEditorScope"
+            description="%makefileEditor.description"
+            id="org.eclipse.cdt.make.ui.makefileEditorScope">
+      </scope>
       <command
             name="%CommandTargetBuild.name"
             description="%CommandTargetBuild.description"
@@ -268,6 +274,19 @@
             command="org.eclipse.cdt.make.ui.edit.text.makefile.uncomment"
             configuration="org.eclipse.ui.defaultAcceleratorConfiguration">
       </keyBinding>
+      <command
+            name="%ActionDefinition.opendecl.name"
+            category="org.eclipse.cdt.make.ui.category.source"
+            description="%ActionDefinition.opendecl.description"
+            id="org.eclipse.cdt.make.ui.edit.text.makefile.opendecl">
+      </command>
+      <keyBinding
+            string="F3"
+            scope="org.eclipse.cdt.make.ui.makefileEditorScope"
+            command="org.eclipse.cdt.make.ui.edit.text.makefile.opendecl"
+            configuration="org.eclipse.ui.defaultAcceleratorConfiguration">
+      </keyBinding>
+      
    </extension>
    <extension
          point="org.eclipse.ui.preferencePages">

build/org.eclipse.cdt.make.ui/src/org/eclipse/cdt/make/internal/ui/editor/IMakefileEditorActionDefinitionIds.java

@@ -21,6 +21,6 @@ public interface IMakefileEditorActionDefinitionIds extends ITextEditorActionDef
 
 	final String COMMENT = "org.eclipse.cdt.make.ui.edit.text.makefile.uncomment"; //$NON-NLS-1$
 
-	final String OPEN_DECLARATION = "org.eclipse.cdt.make.ui.edit.text.makefile.open_declaration"; //$NON-NLS-1$
+	final String OPEN_DECLARATION = "org.eclipse.cdt.make.ui.edit.text.makefile.opendcl"; //$NON-NLS-1$
 
 }

build/org.eclipse.cdt.make.ui/src/org/eclipse/cdt/make/internal/ui/editor/MakefileEditor.java

@@ -25,7 +25,9 @@ import org.eclipse.jface.text.FindReplaceDocumentAdapter;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.IRegion;
 import org.eclipse.jface.text.ITextOperationTarget;
+import org.eclipse.jface.text.ITextViewerExtension;
 import org.eclipse.jface.text.rules.IWordDetector;
+import org.eclipse.jface.text.source.IOverviewRuler;
 import org.eclipse.jface.text.source.ISourceViewer;
 import org.eclipse.jface.text.source.IVerticalRuler;
 import org.eclipse.jface.text.source.SourceViewerConfiguration;
@@ -78,6 +80,33 @@ public class MakefileEditor extends TextEditor implements ISelectionChangedListe
 		}
 	};
 
+	/**
+	 * Adapted source viewer for CEditor
+	 */
+
+	public class AdaptedSourceViewer extends ProjectionViewer implements ITextViewerExtension {
+
+
+		public AdaptedSourceViewer(Composite parent, IVerticalRuler ruler,
+			IOverviewRuler overviewRuler, boolean showsAnnotation, int styles) {
+			super(parent, ruler, overviewRuler, showsAnnotation, styles);
+		}
+
+		/* (non-Javadoc)
+		 * @see org.eclipse.jface.text.source.ISourceViewer#setRangeIndication(int, int, boolean)
+		 */
+		public void setRangeIndication(int offset, int length, boolean moveCursor) {
+			// Fixin a bug in the ProjectViewer implemenation
+			// PR: https://bugs.eclipse.org/bugs/show_bug.cgi?id=72914
+			if (isProjectionMode()) {
+				super.setRangeIndication(offset, length, moveCursor);
+			} else {
+				super.setRangeIndication(offset, length, false);
+			}
+		}
+	}
+
+
 	MakefileSourceConfiguration getMakefileSourceConfiguration() {
 		SourceViewerConfiguration configuration = getSourceViewerConfiguration();
 		if (configuration instanceof MakefileSourceConfiguration) {
@@ -159,7 +188,7 @@ public class MakefileEditor extends TextEditor implements ISelectionChangedListe
 	}
 
 	protected ISourceViewer createSourceViewer(Composite parent, IVerticalRuler ruler, int styles) {
-		ISourceViewer viewer = new ProjectionViewer(parent, ruler, getOverviewRuler(), isOverviewRulerVisible(), styles);
+		ISourceViewer viewer = new AdaptedSourceViewer(parent, ruler, getOverviewRuler(), isOverviewRulerVisible(), styles);
 
 		// ensure decoration support has been created and configured.
 		getSourceViewerDecorationSupport(viewer);

build/org.eclipse.cdt.make.ui/src/org/eclipse/cdt/make/internal/ui/editor/OpenDeclarationAction.java

@@ -10,18 +10,22 @@
  *******************************************************************************/
 package org.eclipse.cdt.make.internal.ui.editor;
 
+import org.eclipse.cdt.core.resources.FileStorage;
+import org.eclipse.cdt.internal.ui.util.ExternalEditorInput;
 import org.eclipse.cdt.make.core.makefile.IDirective;
 import org.eclipse.cdt.make.core.makefile.IMakefile;
 import org.eclipse.cdt.make.internal.ui.MakeUIPlugin;
 import org.eclipse.cdt.make.internal.ui.text.WordPartDetector;
 import org.eclipse.cdt.make.ui.IWorkingCopyManager;
 import org.eclipse.core.resources.IFile;
+import org.eclipse.core.resources.IStorage;
 import org.eclipse.core.runtime.IPath;
 import org.eclipse.core.runtime.Path;
 import org.eclipse.jface.text.IDocument;
 import org.eclipse.jface.text.ITextSelection;
 import org.eclipse.jface.viewers.ISelectionProvider;
 import org.eclipse.ui.IEditorPart;
+import org.eclipse.ui.IStorageEditorInput;
 import org.eclipse.ui.IWorkbenchPage;
 import org.eclipse.ui.PartInitException;
 import org.eclipse.ui.ide.IDE;
@@ -94,6 +98,20 @@ public class OpenDeclarationAction extends TextEditorAction {
 				}
 				return editorPart;
 			}
+		} else {
+			// External file
+			IStorage storage = new FileStorage(path);
+			IStorageEditorInput input = new ExternalEditorInput(storage);
+			IWorkbenchPage p = MakeUIPlugin.getActivePage();
+			if (p != null) {
+				String editorID = "org.eclipse.cdt.make.editor"; //$NON-NLS-1$
+				IEditorPart editorPart = IDE.openEditor(p, input, editorID, true);
+				if (editorPart instanceof MakefileEditor) {
+					((MakefileEditor)editorPart).setSelection(directive, true);
+				}
+				return editorPart;
+			}
+			
 		}
 		return null;
 	}