Empty versus no exception specification, bug 86943.

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/ast2/AST2CPPTests.java

@@ -5962,4 +5962,28 @@ public class AST2CPPTests extends AST2BaseTest {
 	public void testTypeIdForPtrToMember_Bug242197() throws Exception {
 		parseAndCheckBindings(getAboveComment(), ParserLanguage.CPP);
 	}
+	
+	// void test1();
+	// void test2() throw ();
+	// void test3() throw (int);
+	public void testEmptyExceptionSpecification_Bug86943() throws Exception {
+		IASTTranslationUnit tu= parseAndCheckBindings(getAboveComment(), ParserLanguage.CPP);
+
+		IASTSimpleDeclaration d= getDeclaration(tu, 0);
+		ICPPASTFunctionDeclarator fdtor= (ICPPASTFunctionDeclarator) d.getDeclarators()[0];
+		IASTTypeId[] specs= fdtor.getExceptionSpecification();
+		assertEquals(0, specs.length);
+		assertSame(ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION, specs);
+
+		d= getDeclaration(tu, 1);
+		fdtor= (ICPPASTFunctionDeclarator) d.getDeclarators()[0];
+		specs= fdtor.getExceptionSpecification();
+		assertEquals(0, specs.length);
+		assertNotSame(ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION, specs);
+
+		d= getDeclaration(tu, 2);
+		fdtor= (ICPPASTFunctionDeclarator) d.getDeclarators()[0];
+		specs= fdtor.getExceptionSpecification();
+		assertEquals(1, specs.length);
+	}
 }

core/org.eclipse.cdt.core.tests/parser/org/eclipse/cdt/core/parser/tests/rewrite/changegenerator/remove/ExceptionTest.java

@@ -31,7 +31,7 @@ public class ExceptionTest extends ChangeGeneratorTest {
 	@Override
 	protected void setUp() throws Exception {
 		source = "void foo(int parameter) throw (int){\n}\n\n"; //$NON-NLS-1$
-		expectedSource = "void foo(int parameter){\n}\n\n"; //$NON-NLS-1$
+		expectedSource = "void foo(int parameter) throw (){\n}\n\n"; //$NON-NLS-1$
 		super.setUp();
 	}
 

core/org.eclipse.cdt.core/model/org/eclipse/cdt/internal/core/model/ASTStringUtil.java

@@ -295,14 +295,15 @@ public class ASTStringUtil {
 						buffer.append("=0 "); //$NON-NLS-1$
 					}
 					final IASTTypeId[] exceptionTypeIds= cppFunctionDecl.getExceptionSpecification();
-					if (exceptionTypeIds.length > 0) {
+					if (exceptionTypeIds != ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION) {
-						buffer.append(Keywords.THROW).append(' ');
+						buffer.append(Keywords.THROW).append(" ("); //$NON-NLS-1$
 						for (int i= 0; i < exceptionTypeIds.length; i++) {
 							if (i > 0) {
 								buffer.append(COMMA_SPACE);
 							}
 							appendTypeIdString(buffer, exceptionTypeIds[i]);
 						}
+						buffer.append(')');
 					}
 				}
 			} else if (declarator instanceof IASTFieldDeclarator) {

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/dom/ast/cpp/ICPPASTFunctionDeclarator.java

@@ -22,6 +22,12 @@ import org.eclipse.cdt.core.dom.ast.IASTTypeId;
  */
 public interface ICPPASTFunctionDeclarator extends IASTStandardFunctionDeclarator {
 
+	/**
+	 * Used as return value for {@link #getExceptionSpecification()}.
+	 * @since 5.1
+	 */
+	public static final IASTTypeId[] NO_EXCEPTION_SPECIFICATION = {};
+
 	/**
 	 * <code>EXCEPTION_TYPEID</code> represents the type IDs throws in the
 	 * exception specification.
@@ -60,7 +66,9 @@ public interface ICPPASTFunctionDeclarator extends IASTStandardFunctionDeclarato
 	public void setPureVirtual(boolean isPureVirtual);
 
 	/**
-	 * Get the exception specification.
+	 * Returns an array of type-ids representing the exception specification. The return value
+	 * {@link #NO_EXCEPTION_SPECIFICATION} indicates that no exceptions are specified, whereas
+	 * {@link IASTTypeId#EMPTY_TYPEID_ARRAY} is used for an empty exception specification.
 	 */
 	public IASTTypeId[] getExceptionSpecification();
 
@@ -69,6 +77,13 @@ public interface ICPPASTFunctionDeclarator extends IASTStandardFunctionDeclarato
 	 */
 	public void addExceptionSpecificationTypeId(IASTTypeId typeId);
 
+	/**
+	 * Configures the declarator with an empty exception specification (as opposed to having none). 
+	 * 
+	 * @since 5.1
+	 */
+	public void setEmptyExceptionSpecification();
+	
 	/**
 	 * Get function scope this node represents. Returns <code>null</code>, if this declarator does not
 	 * declare a function-prototype or function-definition.

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/core/parser/util/ArrayUtil.java

@@ -284,14 +284,12 @@ public class ArrayUtil {
 	 * The position of the last non-null element in the array must also be known. 
 	 */
 	public static Object[] removeNullsAfter(Class<?> c, Object[] array, int index) {
-        if( array == null || index < 0)
-            return (Object[]) Array.newInstance( c, 0 );
-        
         final int newLen= index+1;
-        if( array.length == newLen)
+        if (array != null && array.length == newLen)
 			return array;
         
         Object[] newArray = (Object[]) Array.newInstance(c, newLen);
+        if (array != null && newLen > 0)
         	System.arraycopy(array, 0, newArray, 0, newLen);
 		return newArray;
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/CPPASTFunctionDeclarator.java

@@ -29,7 +29,7 @@ import org.eclipse.cdt.internal.core.dom.parser.cpp.semantics.CPPVisitor;
 public class CPPASTFunctionDeclarator extends CPPASTDeclarator implements ICPPASTFunctionDeclarator {
     private IASTParameterDeclaration[] parameters = null;
     private int parametersPos = -1;
-    private IASTTypeId[] typeIds = null;
+    private IASTTypeId[] typeIds = NO_EXCEPTION_SPECIFICATION;
     private int typeIdsPos = -1;
     
     private boolean varArgs;
@@ -86,12 +86,13 @@ public class CPPASTFunctionDeclarator extends CPPASTDeclarator implements ICPPAS
     }
 
     public IASTTypeId[] getExceptionSpecification() {
-        if (typeIds == null) 
-        	return IASTTypeId.EMPTY_TYPEID_ARRAY;
-        
         return typeIds= ArrayUtil.trimAt(IASTTypeId.class, typeIds, typeIdsPos);
     }
     
+    public void setEmptyExceptionSpecification() {
+    	typeIds= IASTTypeId.EMPTY_TYPEID_ARRAY;
+    }
+
     public void addExceptionSpecificationTypeId(IASTTypeId typeId) {
     	if (typeId != null) {
     		typeIds = (IASTTypeId[]) ArrayUtil.append(IASTTypeId.class, typeIds, ++typeIdsPos, typeId);

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/parser/cpp/GNUCPPSourceParser.java

@@ -170,9 +170,7 @@ import org.eclipse.cdt.internal.core.parser.token.TokenFactory;
 public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
     private static final int DEFAULT_PARM_LIST_SIZE = 4;
     private static final int DEFAULT_POINTEROPS_LIST_SIZE = 4;
-    private static final int DEFAULT_SIZE_EXCEPTIONS_LIST = 2;
     private static final int DEFAULT_CATCH_HANDLER_LIST_SIZE= 4;
-    private static final int DEFAULT_PARAMETER_LIST_SIZE= 4;
     private static final ASTVisitor EMPTY_VISITOR = new ASTVisitor() {};
     private static enum DtorStrategy {PREFER_FUNCTION, PREFER_NESTED}
 
@@ -3434,10 +3432,9 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 		IToken last = consume(IToken.tLPAREN);
 		int startOffset= last.getOffset();
 		boolean seenParameter= false;
-		boolean encounteredVarArgs= false;
-		List<IASTParameterDeclaration> parameters= null;
 		int endOffset= last.getEndOffset();
 		
+		final ICPPASTFunctionDeclarator fc= createFunctionDeclarator();
 		paramLoop: while(true) {
 			switch (LT(1)) {
 			case IToken.tRPAREN:
@@ -3446,7 +3443,7 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 				break paramLoop;
 			case IToken.tELLIPSIS:
 				endOffset= consume().getEndOffset();
-				encounteredVarArgs = true;
+				fc.setVarArgs(true);
 				break;
 			case IToken.tCOMMA:
 				endOffset= consume().getEndOffset();
@@ -3457,10 +3454,8 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 					throwBacktrack(startOffset, endOffset - startOffset);
 			
 				IASTParameterDeclaration pd = parameterDeclaration();
+				fc.addParameterDeclaration(pd);
 				endOffset = calculateEndOffset(pd);
-				if (parameters == null)
-					parameters = new ArrayList<IASTParameterDeclaration>(DEFAULT_PARAMETER_LIST_SIZE);
-				parameters.add(pd);
 				seenParameter = true;
 				break;
 			}
@@ -3469,20 +3464,15 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 		// Consume any number of __attribute__ tokens after the parameters
 		__attribute_decl_seq(supportAttributeSpecifiers, false);
 
-		boolean isConst= false;
-		boolean isVolatile= false;
-		boolean isPureVirtual= false;
-		ArrayList<IASTTypeId> exceptionSpecIds= null;
-
 		// cv-qualifiers
 		cvloop: while(true) {
 			switch(LT(1)) {
 			case IToken.t_const:
-				isConst= true;
+			    fc.setConst(true);
 				endOffset= consume().getEndOffset();
 				break;
 			case IToken.t_volatile:
-				isVolatile= true;
+			    fc.setVolatile(true);
 				endOffset= consume().getEndOffset();
 				break;
 			default:
@@ -3492,7 +3482,7 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 
 		// throws clause
 		if (LT(1) == IToken.t_throw) {
-			exceptionSpecIds = new ArrayList<IASTTypeId>(DEFAULT_SIZE_EXCEPTIONS_LIST);
+			fc.setEmptyExceptionSpecification();
 			consume(); // throw
 			consume(IToken.tLPAREN); 
 
@@ -3509,7 +3499,7 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 					int thoffset= LA(1).getOffset();
 				IASTTypeId typeId= typeId(DeclarationOptions.TYPEID);
 				if (typeId != null) {
-					exceptionSpecIds.add(typeId);
+					fc.addExceptionSpecificationTypeId(typeId);
 				} else {
 					int thendoffset= LA(1).getOffset();
 					if (thoffset == thendoffset) {
@@ -3519,7 +3509,7 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 					IASTProblemTypeId typeIdProblem = createTypeIDProblem();
 					typeIdProblem.setProblem(p);
 					((ASTNode) typeIdProblem).setOffsetAndLength(((ASTNode) p));
-					exceptionSpecIds.add(typeIdProblem);
+					fc.addExceptionSpecificationTypeId(typeIdProblem);
 				}
 				break;
 				}
@@ -3535,24 +3525,10 @@ public class GNUCPPSourceParser extends AbstractGNUSourceCodeParser {
 			if (image.length == 1 && image[0] == '0') {
 				consume(); // tASSIGN
 				endOffset= consume().getEndOffset(); // tINTEGER
-				isPureVirtual= true;
+			    fc.setPureVirtual(true);
 			}
 		}
 
-		final ICPPASTFunctionDeclarator fc= createFunctionDeclarator();
-		fc.setVarArgs(encounteredVarArgs);
-	    fc.setConst(isConst);
-	    fc.setVolatile(isVolatile);
-	    fc.setPureVirtual(isPureVirtual);
-	    if (parameters != null) {
-	    	for (IASTParameterDeclaration param : parameters) {
-	    		fc.addParameterDeclaration(param);
-	    	}
-	    }
-	    if (exceptionSpecIds != null)
-		for (IASTTypeId exception : exceptionSpecIds) {
-	        fc.addExceptionSpecificationTypeId(exception);
-		}
         ((ASTNode) fc).setOffsetAndLength(startOffset, endOffset-startOffset);
         return fc;
 	}

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/astwriter/DeclaratorWriter.java

@@ -146,7 +146,7 @@ public class DeclaratorWriter extends NodeWriter {
 	}
 
 	protected void writeExceptionSpecification(ICPPASTFunctionDeclarator funcDec, IASTTypeId[] exceptions) {
-		if(exceptions.length != 0) {
+		if (exceptions != ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION) {
 			scribe.printSpace();
 			scribe.print(THROW);
 			scribe.print('(');

core/org.eclipse.cdt.core/parser/org/eclipse/cdt/internal/core/dom/rewrite/changegenerator/ModifiedASTDeclaratorWriter.java

@@ -65,6 +65,13 @@ public class ModifiedASTDeclaratorWriter extends DeclaratorWriter {
 	@Override
 	protected void writeExceptionSpecification(ICPPASTFunctionDeclarator funcDec, IASTTypeId[] exceptions ) {	
 		IASTTypeId[] modifiedExceptions = modificationHelper.createModifiedChildArray(funcDec, exceptions, IASTTypeId.class);
+		// it makes a difference whether the exception array is identical to 
+		// ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION
+		if (modifiedExceptions.length == 0 &&
+				exceptions == ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION) {
+			modifiedExceptions= ICPPASTFunctionDeclarator.NO_EXCEPTION_SPECIFICATION;
+		}
+		
 		super.writeExceptionSpecification(funcDec, modifiedExceptions);
 	}