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Bug 515536

Summary:

"Method parameter not used" warning incorrectly disappears when @param in javadoc

Product:

[Eclipse Project] JDT

Reporter:

Shawn Heisey <eclipse>

Component:

Core

Assignee:

Till Brychcy <register.eclipse>

Status:

CLOSED INVALID

QA Contact:

Severity:

normal

Priority:

CC:

jarthana, register.eclipse, stephan.herrmann

Version:

4.6

Target Milestone:

4.7 M7

Hardware:

OS:

Windows 7

Whiteboard:

Attachments:

Description	Flags
Error/Warning preferences screenshot	none

Description Shawn Heisey

2017-04-20 13:40:59 EDT

Eclipse 4.6.3, Java EE development package.

I have the setting turned on that marks unused method parameters with a warning.

I've discovered that if the method has javadoc and a parameter is referenced with the @param annotation in the javadoc, but is completely unused inside the method, the unused warning isn't shown.

I do not think that mention in javadoc @param should be enough to disable the warning about the parameter being unused.

Comment 1 Jay Arthanareeswaran

2017-04-21 05:16:33 EDT

Stephan, what's your take here?

Comment 2 Shawn Heisey

2017-04-21 10:12:22 EDT

When I opened this, I did realize that this isn't going to be a trivial change.  Likely what's happening is that the code is counting usages and the warning goes away when the number is above zero.

Best guess is that a fix would involve either having multiple usage counters or simply not counting @param usages.  It might be challenging with the latter solution to make sure they are still highlighted when the variable is clicked.  I have not examined the code at all, so this assessment could very well be wrong.

Comment 3 Till Brychcy

2017-04-21 14:21:17 EDT

There's a setting for that:
Go to Preferences > Java > Compiler > Error / Warnings, Section "Unnecessary Code"
deselect "Ignore unused parameters documented with '@param' tag"

Comment 4 Shawn Heisey

2017-04-21 16:03:26 EDT

Created attachment 267916 [details]
Error/Warning preferences screenshot

This shows that the @param-related checkbox is unchecked in the Errors/Warnings preferences screen.

Comment 5 Shawn Heisey

2017-04-21 16:04:30 EDT

I found that @param setting in the preferences and unchecked it, then let it rebuild the workspace.  There's still not a warning on a parameter that is unused other than the @param mention.

Comment 6 Shawn Heisey

2017-04-21 16:06:30 EDT

PEBCAK.  There were project-specific settings.  Changed that option there and now it's working.  Closing the bug.