X10

Null pointer exception in X10DocProvider

Details

  • Type: Bug Bug
  • Status: Closed Closed
  • Priority: Major Major
  • Resolution: Fixed
  • Affects Version/s: X10 2.0.2
  • Fix Version/s: X10 2.0.3
  • Component/s: X10DT Source Editor
  • Labels:
    None
  • Environment:
    win/cygwin
  • Number of attachments :
    0

Description

When I hover, or click anywhere on the line declaring the field: "var f: Hello;", I get the following exception:

Universal Editor Error
java.lang.NullPointerException
at org.eclipse.imp.x10dt.ui.editor.X10DocProvider.getHelpForEntity(X10DocProvider.java:316)
at org.eclipse.imp.x10dt.ui.editor.X10DocProvider.getDocumentation(X10DocProvider.java:85)
at org.eclipse.imp.editor.HoverHelper.getHoverHelpAt(HoverHelper.java:86)
at org.eclipse.imp.editor.internal.HoverHelpController.getHoverInfo(HoverHelpController.java:59)
at org.eclipse.jface.text.TextViewerHoverManager$4.run(TextViewerHoverManager.java:168)

The code is the following. Note that this problem occurs only when there is a compilation error (line "h = "). But not all compilation errors produce this behavior.

Hello.x10
import x10.io.Console; 

public class Hello {
	var f: Hello;
    
    public static def main(args:Rail[String]!){
         if(args.length>0){
           Console.OUT.println("The first arg is: "+args(0));
         } 
         Console.OUT.println("Hello X10 world ");
         val h = new Hello();  // final variable 
         var result : Boolean = h.myMethod(); // mutable variable 
         h = 
         Console.OUT.println("The answer is: "+result);
    } 
    /** x10doc comment for myMethod */;
    public def myMethod()=true;
}

Issue Links

depends upon

Bug - A problem which impairs or prevents the functions of the product. XTENLANG-1219 The type checker needs to set the AST appropriately in the presence of compilation error

  • Major - Major loss of function.
  • Closed - The issue is considered finished, the resolution is correct. Issues which are not closed can be reopened.

Activity

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Robert M. Fuhrer added a comment -

This seems to be a problem regardless of whether there's a compilation error. I'm running X10DT from HEAD of SVN trunk, and I get the error in a cleanly-compiling editor source buffer, pretty much no matter where I click.

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Robert M. Fuhrer added a comment - This seems to be a problem regardless of whether there's a compilation error. I'm running X10DT from HEAD of SVN trunk, and I get the error in a cleanly-compiling editor source buffer, pretty much no matter where I click.
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Mandana Vaziri added a comment -

This bug happens when there is a compilation error. Since we don't have error recovery yet, I added a catch clause to make the NPE silently go away for now. So Hover Help now does not work in the presence of compilation errors.

Revision 13586.

Show
Mandana Vaziri added a comment - This bug happens when there is a compilation error. Since we don't have error recovery yet, I added a catch clause to make the NPE silently go away for now. So Hover Help now does not work in the presence of compilation errors. Revision 13586.
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Mandana Vaziri added a comment -

To respond to Bob's comment above:

A different fix to the Hover Help fixed the problem of throwing NPEs when there are no compilation errors.

Show
Mandana Vaziri added a comment - To respond to Bob's comment above: A different fix to the Hover Help fixed the problem of throwing NPEs when there are no compilation errors.
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Mandana Vaziri added a comment -

Re-opening issue – The specification for Hover Help is to provide partial correct information in the presence of compilation errors. So in a circumstance where an NPE is normally thrown, we need to figure what information exists on a case by case basis to see what kind of partial information could be safely given to the user.

This specification also implies that the integration of X10Doc with Hover Help is not as straightforward as I had initially thought. The refactoring of X10Doc to provide an API for getting doc programmatically will now need therefore to support partial information.

Show
Mandana Vaziri added a comment - Re-opening issue – The specification for Hover Help is to provide partial correct information in the presence of compilation errors. So in a circumstance where an NPE is normally thrown, we need to figure what information exists on a case by case basis to see what kind of partial information could be safely given to the user. This specification also implies that the integration of X10Doc with Hover Help is not as straightforward as I had initially thought. The refactoring of X10Doc to provide an API for getting doc programmatically will now need therefore to support partial information.
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Mandana Vaziri added a comment -

NPEs in Hover Help are caused by a bug in the front end: the type checker does not set the AST appropriately in the presence of semantic compilation errors. So the AST retrieved by the Parse Controller is missing a lot of type information. (XTENLANG-1219)

Show
Mandana Vaziri added a comment - NPEs in Hover Help are caused by a bug in the front end: the type checker does not set the AST appropriately in the presence of semantic compilation errors. So the AST retrieved by the Parse Controller is missing a lot of type information. ( XTENLANG-1219 )
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Robert M. Fuhrer added a comment -

Now traps NPE's as it used to.

Show
Robert M. Fuhrer added a comment - Now traps NPE's as it used to.
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David Grove added a comment -

bulk close of resolved issues in 2.0.3.

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David Grove added a comment - bulk close of resolved issues in 2.0.3.

People

  • Assignee:
    Mandana Vaziri
    Reporter:
    Mandana Vaziri
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Dates

  • Created:
    Updated:
    Resolved: