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When attempting to Infer Generic Type Arguments... (via. refactor menu) on a class that contains a call to Object.getClass(), an "unexpected exception" occours, and refactoring aborts. This occoured in real-world code (I'm not even going to comment on the quality of the code, or whether the call to getClass() was even necessary) in JavaCC's org.javacc.parser.Options class: https://javacc.dev.java.net/source/browse/javacc/src/org/javacc/parser/Options.java?rev=1.18&view=markup A far simpler test-case is reproduced below. -- To reproduce: 1) Create or open any Java/JDT project. 2) Create a class that looks something like (or simply add the method to any other class): class TrivialClass { void irrelevant(Object someObject) { someObject.getClass(); } } 3) Right-click the editor (or use a hotkey etc.) -> Refactor -> Infer Generic Type Arguments... 4) The check-boxes on the dialog are irrelevant. Press "Preview >" or "OK". 5) Observe either: 5a) From Preview >: A fatal error occoured while performing the refactoring. Found problems: An unexpected exception occurred while creating a change object. See the error log for more details. No context information available. 5b) From OK: An unexpected exception occurred while perfomring the refactoring. See the error log for more details. See the error log for more details. 6) Look at the error log. (reproduced below) -- Notes - It's incredibly hard to work out where problems like this happen, especially if you're running refactoring options on entire source trees. A helpful error message in case of unexpected situations would be nice, but is probably far too much work. :) - It doesn't happen if you replace Object with, say, Integer. -- System: - Eclipse: Version: 3.3.1.1 Build id: M20071023-1652 x86 (x32) architecture. - Java: java version "1.6.0_03" Java(TM) SE Runtime Environment (build 1.6.0_03-b05) Java HotSpot(TM) Client VM (build 1.6.0_03-b05, mixed mode, sharing) x86 (x32) architecture. - Windows: Vista. Microsoft Windows [Version 6.0.6000] x64 (x86_64) architecture/edition. -- Full .log for OK: !SESSION 2007-11-27 08:52:05.189 ----------------------------------------------- eclipse.buildId=M20071023-1652 java.version=1.6.0_03 java.vendor=Sun Microsystems Inc. BootLoader constants: OS=win32, ARCH=x86, WS=win32, NL=en_GB Command-line arguments: -os win32 -ws win32 -arch x86 !ENTRY org.eclipse.ltk.ui.refactoring 4 10000 2007-11-27 08:53:16.334 !MESSAGE Internal Error !STACK 0 java.lang.reflect.InvocationTargetException at org.eclipse.jface.operation.ModalContext.run(ModalContext.java:350) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.run(RefactoringWizardDialog2.java:310) at org.eclipse.ltk.ui.refactoring.RefactoringWizard.internalPerformFinish(RefactoringWizard.java:553) at org.eclipse.ltk.ui.refactoring.UserInputWizardPage.performFinish(UserInputWizardPage.java:154) at org.eclipse.ltk.ui.refactoring.RefactoringWizard.performFinish(RefactoringWizard.java:619) at org.eclipse.ltk.internal.ui.refactoring.RefactoringWizardDialog2.okPressed(RefactoringWizardDialog2.java:439) at org.eclipse.jface.dialogs.Dialog.buttonPressed(Dialog.java:464) at org.eclipse.jface.dialogs.Dialog$2.widgetSelected(Dialog.java:616) at org.eclipse.swt.widgets.TypedListener.handleEvent(TypedListener.java:227) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293) at org.eclipse.jface.window.Window.runEventLoop(Window.java:820) at org.eclipse.jface.window.Window.open(Window.java:796) at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation$1.run(RefactoringWizardOpenOperation.java:142) at org.eclipse.swt.custom.BusyIndicator.showWhile(BusyIndicator.java:67) at org.eclipse.ltk.ui.refactoring.RefactoringWizardOpenOperation.run(RefactoringWizardOpenOperation.java:154) at org.eclipse.jdt.internal.ui.refactoring.actions.RefactoringStarter.activate(RefactoringStarter.java:49) at org.eclipse.jdt.internal.corext.refactoring.RefactoringExecutionStarter.startInferTypeArgumentsRefactoring(RefactoringExecutionStarter.java:312) at org.eclipse.jdt.ui.actions.InferTypeArgumentsAction.run(InferTypeArgumentsAction.java:133) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.dispatchRun(SelectionDispatchAction.java:272) at org.eclipse.jdt.ui.actions.SelectionDispatchAction.run(SelectionDispatchAction.java:244) at org.eclipse.jface.action.Action.runWithEvent(Action.java:498) at org.eclipse.jface.action.ActionContributionItem.handleWidgetSelection(ActionContributionItem.java:546) at org.eclipse.jface.action.ActionContributionItem.access$2(ActionContributionItem.java:490) at org.eclipse.jface.action.ActionContributionItem$5.handleEvent(ActionContributionItem.java:402) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:938) at org.eclipse.swt.widgets.Display.runDeferredEvents(Display.java:3682) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3293) at org.eclipse.jdt.internal.ui.actions.QuickMenuAction.run(QuickMenuAction.java:75) at org.eclipse.jface.action.Action.runWithEvent(Action.java:498) at org.eclipse.jface.commands.ActionHandler.execute(ActionHandler.java:119) at org.eclipse.core.commands.Command.executeWithChecks(Command.java:475) at org.eclipse.core.commands.ParameterizedCommand.executeWithChecks(ParameterizedCommand.java:429) at org.eclipse.ui.internal.handlers.HandlerService.executeCommand(HandlerService.java:165) at org.eclipse.ui.internal.keys.WorkbenchKeyboard.executeCommand(WorkbenchKeyboard.java:470) at org.eclipse.ui.internal.keys.WorkbenchKeyboard.press(WorkbenchKeyboard.java:821) at org.eclipse.ui.internal.keys.WorkbenchKeyboard.processKeyEvent(WorkbenchKeyboard.java:879) at org.eclipse.ui.internal.keys.WorkbenchKeyboard.filterKeySequenceBindings(WorkbenchKeyboard.java:568) at org.eclipse.ui.internal.keys.WorkbenchKeyboard.access$3(WorkbenchKeyboard.java:510) at org.eclipse.ui.internal.keys.WorkbenchKeyboard$KeyDownFilter.handleEvent(WorkbenchKeyboard.java:126) at org.eclipse.swt.widgets.EventTable.sendEvent(EventTable.java:66) at org.eclipse.swt.widgets.Display.filterEvent(Display.java:1141) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:937) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:962) at org.eclipse.swt.widgets.Widget.sendEvent(Widget.java:947) at org.eclipse.swt.widgets.Control.traverse(Control.java:3385) at org.eclipse.swt.widgets.Control.translateMnemonic(Control.java:3229) at org.eclipse.swt.widgets.Composite.translateMnemonic(Composite.java:948) at org.eclipse.swt.widgets.Control.translateMnemonic(Control.java:3247) at org.eclipse.swt.widgets.Display.translateMnemonic(Display.java:4186) at org.eclipse.swt.widgets.Display.filterMessage(Display.java:1155) at org.eclipse.swt.widgets.Display.readAndDispatch(Display.java:3289) at org.eclipse.ui.internal.Workbench.runEventLoop(Workbench.java:2389) at org.eclipse.ui.internal.Workbench.runUI(Workbench.java:2353) at org.eclipse.ui.internal.Workbench.access$4(Workbench.java:2219) at org.eclipse.ui.internal.Workbench$4.run(Workbench.java:466) at org.eclipse.core.databinding.observable.Realm.runWithDefault(Realm.java:289) at org.eclipse.ui.internal.Workbench.createAndRunWorkbench(Workbench.java:461) at org.eclipse.ui.PlatformUI.createAndRunWorkbench(PlatformUI.java:149) at org.eclipse.ui.internal.ide.application.IDEApplication.start(IDEApplication.java:106) at org.eclipse.equinox.internal.app.EclipseAppHandle.run(EclipseAppHandle.java:169) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.runApplication(EclipseAppLauncher.java:106) at org.eclipse.core.runtime.internal.adaptor.EclipseAppLauncher.start(EclipseAppLauncher.java:76) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:363) at org.eclipse.core.runtime.adaptor.EclipseStarter.run(EclipseStarter.java:176) at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method) at sun.reflect.NativeMethodAccessorImpl.invoke(Unknown Source) at sun.reflect.DelegatingMethodAccessorImpl.invoke(Unknown Source) at java.lang.reflect.Method.invoke(Unknown Source) at org.eclipse.equinox.launcher.Main.invokeFramework(Main.java:508) at org.eclipse.equinox.launcher.Main.basicRun(Main.java:447) at org.eclipse.equinox.launcher.Main.run(Main.java:1173) Caused by: java.lang.UnsupportedOperationException at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.types.WildcardType.getSubTypes(WildcardType.java:39) at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.SubTypesOfSingleton.isSingleton(SubTypesOfSingleton.java:226) at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet.superTypes(TypeSet.java:163) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.maintainSimpleConstraint(InferTypeArgumentsConstraintsSolver.java:248) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.processConstraints(InferTypeArgumentsConstraintsSolver.java:224) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.runSolver(InferTypeArgumentsConstraintsSolver.java:201) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.solveConstraints(InferTypeArgumentsConstraintsSolver.java:128) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsRefactoring.checkFinalConditions(InferTypeArgumentsRefactoring.java:228) at org.eclipse.ltk.core.refactoring.CheckConditionsOperation.run(CheckConditionsOperation.java:83) at org.eclipse.ltk.core.refactoring.CreateChangeOperation.run(CreateChangeOperation.java:118) at org.eclipse.ltk.core.refactoring.PerformChangeOperation.run(PerformChangeOperation.java:209) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1797) at org.eclipse.ltk.internal.ui.refactoring.WorkbenchRunnableAdapter.run(WorkbenchRunnableAdapter.java:87) at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:113) Root exception: java.lang.UnsupportedOperationException at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.types.WildcardType.getSubTypes(WildcardType.java:39) at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.SubTypesOfSingleton.isSingleton(SubTypesOfSingleton.java:226) at org.eclipse.jdt.internal.corext.refactoring.typeconstraints.typesets.TypeSet.superTypes(TypeSet.java:163) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.maintainSimpleConstraint(InferTypeArgumentsConstraintsSolver.java:248) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.processConstraints(InferTypeArgumentsConstraintsSolver.java:224) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.runSolver(InferTypeArgumentsConstraintsSolver.java:201) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsConstraintsSolver.solveConstraints(InferTypeArgumentsConstraintsSolver.java:128) at org.eclipse.jdt.internal.corext.refactoring.generics.InferTypeArgumentsRefactoring.checkFinalConditions(InferTypeArgumentsRefactoring.java:228) at org.eclipse.ltk.core.refactoring.CheckConditionsOperation.run(CheckConditionsOperation.java:83) at org.eclipse.ltk.core.refactoring.CreateChangeOperation.run(CreateChangeOperation.java:118) at org.eclipse.ltk.core.refactoring.PerformChangeOperation.run(PerformChangeOperation.java:209) at org.eclipse.core.internal.resources.Workspace.run(Workspace.java:1797) at org.eclipse.ltk.internal.ui.refactoring.WorkbenchRunnableAdapter.run(WorkbenchRunnableAdapter.java:87) at org.eclipse.jface.operation.ModalContext$ModalContextThread.run(ModalContext.java:113)
Duplicated with older Eclipse on linux: -- Eclipse: Version: 3.2.1 Build id: M20060921-0945 (Debian version: 3.2.1-4) -- Java: java version "1.6.0" Java(TM) SE Runtime Environment (build 1.6.0-b105) Java HotSpot(TM) 64-Bit Server VM (build 1.6.0-b105, mixed mode) -- Linux: Linux ponies 2.6.22-2-amd64 #1 SMP Thu Aug 30 23:43:59 UTC 2007 x86_64 GNU/Linux Debian: blend of stable and testing.
Moving to JDT/UI
*** Bug 216661 has been marked as a duplicate of this bug. ***
*** Bug 190508 has been marked as a duplicate of this bug. ***
See simple test case in bug 211037 comment 0.
I got the same one on OS: xp Version: 3.4.0 Build id: I20080222-1622
Created attachment 102002 [details] Fix This only happens with a 1.6 JRE, where Object#getClass() has return type Class<?>. In 1.5, the return type was Class<? extends Object>. The fix makes UnboundWildcardType#getSubTypes() behave like ExtendsWildcardType#getSubTypes(), which is to return the bound (java.lang.Object in this case). Since the problem only occurs with a 1.6 JRE but our test environment has not been updated to 1.6, the regression test does not really test the broken scenario. I've opened bug 233982 to update the test framework.
Martin, shall we fix this for RC3?
I'd rather see a fix targeted for 'getClass'...
Created attachment 102622 [details] Fix 2 (fails) Here's another fix attempt. It currently fails because of bug 234609.
Created attachment 102635 [details] Fix 3 > I'd rather see a fix targeted for 'getClass'... You're right. Actually, this is a problem in the AST, see bug 234619. This patch is a minimal workaround that only applies for getClass(). It just omits the constraint for the type parameter, which in the end leaves the class raw. This is much better than the UnsupportedOperationException.
patch is good, +1 for 3.4 RC3
+1
Released Fix 3.
Verified in I20080529-1806.
