Bug 486682 - Syntax coloring of macro arguments that occur in reverse order in the AST

This patch also fixes a couple of other bugs related to syntax coloring of
macro expansions, which are exposed by this change (bug 490415, bug 496696).

Change-Id: I3c0030ff61e721e099dc50afc109dd44e37276a3

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/parser/scanner/ASTPreprocessorName.java

@@ -30,7 +30,7 @@ import org.eclipse.core.runtime.IAdaptable;
  * Models IASTNames as needed for the preprocessor statements and macro expansions.
  * @since 5.0
  */
-class ASTPreprocessorName extends ASTPreprocessorNode implements IASTName {
+public class ASTPreprocessorName extends ASTPreprocessorNode implements IASTName {
 	private final char[] fName;
 	private final IBinding fBinding;
 
@@ -236,6 +236,16 @@ class ASTMacroReferenceName extends ASTPreprocessorName {
 			}
 			return null;
 		}
-		return super.getImageLocation();
+		// ASTNode.getImageLocation() computes an image location based on the node location.
+		// Macro reference names which are nested references rather than the name of the
+		// macro being expanded itself, have their node location set to the entire macro
+		// expansion (see LocationMap.pushMacroExpansion()), which doesn't produce a
+		// useful image location. 
+		if (getParent() instanceof ASTMacroExpansion) {
+			if (((ASTMacroExpansion) getParent()).getContext().getMacroReference() == this) {
+				return super.getImageLocation();
+			}
+		}
+		return null;
 	}
 }

core/org.eclipse.cdt.ui.tests/ui/org/eclipse/cdt/ui/tests/text/SemanticHighlightingTest.java

@@ -569,4 +569,37 @@ public class SemanticHighlightingTest extends TestCase {
     public void testVariableTemplates_486672() throws Exception {
     	makeAssertions();
     }
+    
+    //	#define MACRO(Name, Type) Type Name();           //$macroDefinition
+    //	typedef int Int;                                 //$typedef
+    //	class S {                                        //$class
+    //		MACRO(foo, Int)                              //$macroSubstitution,methodDeclaration,typedef
+    //	};
+    public void testMethodNameInsideMacro_486682() throws Exception {
+    	makeAssertions();
+    }
+    
+	//	#define IF_0(t, f) f                             //$macroDefinition
+	//	#define IF(bit, t, f) IF_ ## bit(t, f)           //$macroDefinition
+	//	#define WALDO                                    //$macroDefinition
+	//	#define MAIN(...) int main() { __VA_ARGS__ }     //$macroDefinition
+	//	
+	//	MAIN                                             //$macroSubstitution
+	//	(
+	//	    int x;                                       //$localVariableDeclaration
+	//	    IF(0, WALDO, WALDO)                          //$macroSubstitution,macroSubstitution,macroSubstitution
+	//	)
+    public void testLexicalColoringInsideMacroExpansion_490415() throws Exception {
+    	makeAssertions();
+    }
+    
+    //	#define N1(x) x
+    //	#define M1(x) N1(x)
+    
+    //	int main() {                                     //$functionDeclaration
+    //		M1(0);                                       //$macroSubstitution
+    //	}
+    public void testLexicalColoringInsideMacroExpansion_496696() throws Exception {
+    	makeAssertions();
+    }
 }

core/org.eclipse.cdt.ui/src/org/eclipse/cdt/internal/ui/editor/SemanticHighlightingReconciler.java

@@ -49,6 +49,7 @@ import org.eclipse.cdt.ui.CUIPlugin;
 
 import org.eclipse.cdt.internal.core.dom.parser.ASTNode;
 import org.eclipse.cdt.internal.core.model.ASTCache;
+import org.eclipse.cdt.internal.core.parser.scanner.ASTPreprocessorName;
 
 import org.eclipse.cdt.internal.ui.editor.SemanticHighlightingManager.HighlightedPosition;
 import org.eclipse.cdt.internal.ui.editor.SemanticHighlightingManager.HighlightingStyle;
@@ -67,10 +68,8 @@ public class SemanticHighlightingReconciler implements ICReconcilingListener {
 	private class PositionCollector extends ASTVisitor {
 		/** The semantic token */
 		private SemanticToken fToken= new SemanticToken();
-		private int fMinLocation;
 		
 		public PositionCollector(boolean visitImplicitNames) {
-			fMinLocation= -1;
 			shouldVisitTranslationUnit= true;
 			shouldVisitNames= true;
 			shouldVisitDeclarations= true;
@@ -92,7 +91,6 @@ public class SemanticHighlightingReconciler implements ICReconcilingListener {
 					visitNode(macroDef.getName());
 				}
 			}
-			fMinLocation= -1;
 
 			// Visit macro expansions.
 			IASTPreprocessorMacroExpansion[] macroExps= tu.getMacroExpansions();
@@ -106,7 +104,6 @@ public class SemanticHighlightingReconciler implements ICReconcilingListener {
 					}
 				}
 			}
-			fMinLocation= -1;
 
 			// Visit ordinary code.
 			return super.visit(tu);
@@ -215,11 +212,18 @@ public class SemanticHighlightingReconciler implements ICReconcilingListener {
 				}
 			} else {
 				// Fallback in case no image location available.
-				IASTNodeLocation[] nodeLocations= node.getNodeLocations();
+				// Only use the fallback for nodes that are not preprocessor nodes,
-				if (nodeLocations.length == 1) {
+				// because in the case of nested macro expansions, a preprocessor node 
-					IASTNodeLocation nodeLocation = nodeLocations[0];
+				// can have a node location that is not representative of its actual
-					if (!(nodeLocation instanceof IASTMacroExpansionLocation)) {
+				// image; such nodes should have an image location (accessed via
-						return nodeLocation;
+				// getImageLocation(), above) where appropriate.
+				if (!(node instanceof ASTPreprocessorName)) {
+					IASTNodeLocation[] nodeLocations= node.getNodeLocations();
+					if (nodeLocations.length == 1) {
+						IASTNodeLocation nodeLocation = nodeLocations[0];
+						if (!(nodeLocation instanceof IASTMacroExpansionLocation)) {
+							return nodeLocation;
+						}
 					}
 				}
 			}
@@ -234,12 +238,9 @@ public class SemanticHighlightingReconciler implements ICReconcilingListener {
 		 */
 		private void highlightLocation(IASTNodeLocation nodeLocation, HighlightingStyle highlightingStyle) {
 			int offset= nodeLocation.getNodeOffset();
-			if (offset >= fMinLocation) {
+			int length= nodeLocation.getNodeLength();
-				int length= nodeLocation.getNodeLength();
+			if (offset > -1 && length > 0) {
-				if (offset > -1 && length > 0) {
+				addPosition(offset, length, highlightingStyle);
-					fMinLocation= offset + length;
-					addPosition(offset, length, highlightingStyle);
-				}
 			}
 		}