Fix for 206801: [formatter] Bad formatting with nested template parameters

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/CodeFormatterVisitor.java

@@ -71,6 +71,7 @@ import org.eclipse.cdt.core.dom.ast.IASTPreprocessorStatement;
 import org.eclipse.cdt.core.dom.ast.IASTProblem;
 import org.eclipse.cdt.core.dom.ast.IASTProblemDeclaration;
 import org.eclipse.cdt.core.dom.ast.IASTProblemExpression;
+import org.eclipse.cdt.core.dom.ast.IASTProblemHolder;
 import org.eclipse.cdt.core.dom.ast.IASTProblemStatement;
 import org.eclipse.cdt.core.dom.ast.IASTReturnStatement;
 import org.eclipse.cdt.core.dom.ast.IASTSimpleDeclSpecifier;
@@ -105,10 +106,12 @@ import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTNamespaceDefinition;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTPointerToMember;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTQualifiedName;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTReferenceOperator;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTSimpleTypeTemplateParameter;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateDeclaration;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateId;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateParameter;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateSpecialization;
+import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplatedTypeTemplateParameter;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTUsingDeclaration;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTUsingDirective;
 import org.eclipse.cdt.core.dom.ast.cpp.ICPPASTVisiblityLabel;
@@ -293,7 +296,7 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 				continue;
 			}
 			try {
-				declaration.accept(this);
+				visit(declaration);
 				scribe.startNewLine();
 			} catch (RuntimeException e) {
 				// report, but continue
@@ -320,7 +323,10 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 	public int visit(IASTDeclaration node) {
 		int indentLevel= scribe.indentationLevel;
 		try {
-    		if (node.getNodeLocations()[0] instanceof IASTMacroExpansion) {
+			IASTNodeLocation[] locations= node.getNodeLocations();
+			if (locations.length == 0) {
+				throw new AbortFormatting("Empty location array in " + node.getClass().getName()); //$NON-NLS-1$
+			} else if (locations[0] instanceof IASTMacroExpansion) {
 				skipNode(node);
     		} else
     		if (node instanceof IASTFunctionDefinition) {
@@ -622,7 +628,17 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 	 * @see org.eclipse.cdt.core.dom.ast.ASTVisitor#visit(org.eclipse.cdt.core.dom.ast.IASTTypeId)
 	 */
 	public int visit(IASTTypeId typeId) {
-		formatNode(typeId);
+		if (typeId instanceof IASTProblemHolder) {
+			throw new ASTProblemException(((IASTProblemHolder)typeId).getProblem());
+		}
+		IASTDeclSpecifier declSpec= typeId.getDeclSpecifier();
+		if (declSpec != null) {
+			declSpec.accept(this);
+		}
+		IASTDeclarator declarator= typeId.getAbstractDeclarator();
+		if (declarator != null) {
+			declarator.accept(this);
+		}
 		return PROCESS_SKIP;
 	}
 
@@ -721,8 +737,75 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 	/*
 	 * @see org.eclipse.cdt.core.dom.ast.cpp.CPPASTVisitor#visit(org.eclipse.cdt.core.dom.ast.cpp.ICPPASTTemplateParameter)
 	 */
-	public int visit(ICPPASTTemplateParameter parameter) {
+	public int visit(ICPPASTTemplateParameter node) {
-		formatNode(parameter);
+		try {
+			IASTNodeLocation[] locations= node.getNodeLocations();
+    		if (locations.length == 0) {
+    			return PROCESS_SKIP;
+    		} else if (locations[0] instanceof IASTMacroExpansion) {
+    			skipNode(node);
+    		} else
+    		if (node instanceof ICPPASTSimpleTypeTemplateParameter) {
+    			visit((ICPPASTSimpleTypeTemplateParameter)node);
+    		} else if (node instanceof ICPPASTTemplatedTypeTemplateParameter) {
+    			visit((ICPPASTTemplatedTypeTemplateParameter)node);
+    		} else {
+    			visit((IASTParameterDeclaration)node);
+    		}
+		} catch (ASTProblemException e) {
+			skipNode(node);
+		}
+		return PROCESS_SKIP;
+	}
+
+	public int visit(ICPPASTSimpleTypeTemplateParameter node) {
+		switch (node.getParameterType()) {
+		case ICPPASTSimpleTypeTemplateParameter.st_class:
+			scribe.printNextToken(Token.t_class);
+			scribe.space();
+			break;
+		case ICPPASTSimpleTypeTemplateParameter.st_typename:
+			scribe.printNextToken(Token.t_typename);
+			scribe.space();
+			break;
+		default:
+			assert false : "Unknown template paramter type"; //$NON-NLS-1$
+			formatNode(node);
+			return PROCESS_SKIP;
+		}
+		node.getName().accept(this);
+		IASTTypeId defaultType= node.getDefaultType();
+		if (defaultType != null) {
+			scribe.printNextToken(Token.tASSIGN, scribe.printComment());
+			defaultType.accept(this);
+		}
+		return PROCESS_SKIP;
+	}
+	
+	public int visit(ICPPASTTemplatedTypeTemplateParameter node) {
+		scribe.printNextToken(Token.t_template, scribe.printComment());
+		scribe.printNextToken(Token.tLT, scribe.printComment());
+		if (scribe.printComment()) {
+			scribe.space();
+		}
+		final ICPPASTTemplateParameter[] templateParameters= node.getTemplateParameters();
+		if (templateParameters.length > 0) {
+			final ListAlignment align= new ListAlignment(Alignment.M_COMPACT_SPLIT);
+			formatList(Arrays.asList(templateParameters), align, false, false);
+		}
+		scribe.printNextToken(Token.tGT, scribe.printComment());
+		if (scribe.printComment()) {
+			scribe.space();
+		}
+		IASTName name= node.getName();
+		if (name != null) {
+			name.accept(this);
+		}
+		IASTExpression defaultValue= node.getDefaultValue();
+		if (defaultValue != null) {
+			scribe.printNextToken(Token.tASSIGN, scribe.printComment());
+			defaultValue.accept(this);
+		}
 		return PROCESS_SKIP;
 	}
 	
@@ -979,15 +1062,20 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 	}
 
 	private int visit(ICPPASTTemplateDeclaration node) {
-		scribe.printNextToken(Token.t_template, false);
+		scribe.printNextToken(Token.t_template, scribe.printComment());
-		scribe.printNextToken(Token.tLT, false);
+		scribe.printNextToken(Token.tLT, scribe.printComment());
+		if (scribe.printComment()) {
+			scribe.space();
+		}
 		final ICPPASTTemplateParameter[] templateParameters= node.getTemplateParameters();
 		if (templateParameters.length > 0) {
 			final ListAlignment align= new ListAlignment(Alignment.M_COMPACT_SPLIT);
 			formatList(Arrays.asList(templateParameters), align, false, false);
 		}
-		scribe.printNextToken(Token.tGT, false);
+		scribe.printNextToken(Token.tGT, scribe.printComment());
+		if (scribe.printComment()) {
 			scribe.space();
+		}
 		node.getDeclaration().accept(this);
 		return PROCESS_SKIP;
 	}
@@ -1851,13 +1939,16 @@ public class CodeFormatterVisitor extends CPPASTVisitor {
 	private int visit(ICPPASTTemplateId node) {
 		IASTName name= node.getTemplateName();
 		name.accept(this);
-		scribe.printNextToken(Token.tLT, false);
+		scribe.printNextToken(Token.tLT, scribe.printComment());
+		if (scribe.printComment()) {
+			scribe.space();
+		}
 		final IASTNode[] templateArguments= node.getTemplateArguments();
 		if (templateArguments.length > 0) {
 			final ListAlignment align= new ListAlignment(Alignment.M_COMPACT_SPLIT);
 			formatList(Arrays.asList(templateArguments), align, false, false);
 		}
-		scribe.printNextToken(Token.tGT, false);
+		scribe.printNextToken(Token.tGT, scribe.printComment());
 		return PROCESS_SKIP;
 	}
 

core/org.eclipse.cdt.core/src/org/eclipse/cdt/internal/formatter/Scribe.java

@@ -632,8 +632,10 @@ public class Scribe {
 		try {
 			scanner.resetTo(Math.max(startOffset, scanner.getCurrentPosition()), startOffset + length - 1);
 			int parenLevel= 0;
+			boolean lastTokenWasGT= false;
 			while (true) {
 				boolean hasWhitespace= printComment();
+				boolean isGT= false;
 				currentToken= scanner.nextToken();
 				if (currentToken == null) {
 					if (hasWhitespace) {
@@ -681,6 +683,12 @@ public class Scribe {
 					}
 					print(currentToken.getLength(), hasWhitespace);
 					break;
+				case Token.tGT:
+					if (lastTokenWasGT) {
+						print(currentToken.getLength(), true);
+					}
+					isGT= true;
+					break;
 				case Token.tSEMI:
 					print(currentToken.getLength(), formatter.preferences.insert_space_before_semicolon);
 					break;
@@ -708,6 +716,7 @@ public class Scribe {
 					}
 				}
 				hasWhitespace= false;
+				lastTokenWasGT= isGT;
 			}
 		} finally {
 			scannerEndPosition= savedScannerEndPos;

core/org.eclipse.cdt.ui.tests/resources/formatter/templates/After.cpp

@@ -62,7 +62,7 @@ template<class Bar> void Foo::fum(int i) {
 }
 
 // TEMPLATE_VARIABLES
-template<bool threads, int inst> char
+template <bool threads, int inst> char
 		* default_alloc_template<threads, inst>::S_start_free = 0;
 
 // an instantiation, not a template:

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

@@ -274,4 +274,15 @@ public class CodeFormatterTest extends BaseUITestCase {
 		assertFormatterResult();
 	}
 
+	//template<typename T> class B {};
+	//template<typename T1,typename T2=B<T1> > class A {};
+
+	//template<typename T> class B {
+	//};
+	//template<typename T1, typename T2=B<T1> > class A {
+	//};
+	public void testNestedTemplateParameters_Bug206801() throws Exception {
+		assertFormatterResult();
+	}
+
 }