Feature #5716: duplicated when clause is ignored -> Report which clause it is specifically.

• Status: Closed
• Assignee: ko1 (Koichi Sasada)
• Target version: -

[shevegen (Robert A. Heiler)]

In latest Ruby 1.9.3, if you have warnings enabled, you get information like this here:

foobar.rb:24: warning: duplicated when clause is ignored

This error comes from the file:

compile.c

rb_compile_warning(RSTRING_PTR(iseq->filename), iobj->line_no,
"duplicated when clause is ignored");

This is called, it seems, when the prior function fails:

rb_hash_aset(map, obj, INT2FIX(lobj->position - (pos+len)));

As a user of Ruby, the warning should be better.

Rather than:

foobar.rb:24: warning: duplicated when clause is ignored

I would like to see:

foobar.rb:24: warning: duplicated when clause 'foo' is ignored.

This way, I can scan through the file with the case/when structure
and correct this error. But right now, if you have a very long
case/when structure, you have no idea WHICH clause is duplicated.

The warning message just vaguely says that there is, and this is
not very helpful information.

[mame (Yusuke Endoh)]

• Status changed from Open to Assigned
• Assignee set to ko1 (Koichi Sasada)

[ko1 (Koichi Sasada)]

Thank you for your comment.

I added a small hint on it because if duplicated object was too big, the
output should be ugly.

Does it help you?

sample code

case nil
when 1
when 1, 1
when 1, 1, 1, 1
when 1, 1
end

#=>
../trunk/test.rb:1: warning: duplicated when clause (#1) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#2) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#3) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#4) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#5) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#6) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#7) is ignored
../trunk/test.rb:1: warning: duplicated when clause (#8) is ignored

Patch:
Index: compile.c

--- compile.c (revision 35267)
+++ compile.c (working copy)
@@ -1454,8 +1454,9 @@
rb_hash_aset(map, obj, INT2FIX(lobj->position - (pos+len)));
}
else {

•  		    int n = i/2;
   		    rb_compile_warning(RSTRING_PTR(iseq->filename), iobj->line_no,
  

•  				       "duplicated when clause is ignored");
  

•  				       "duplicated when clause (#%d) is ignored", n);
   		}
   	    }
   	    hide_obj(map);
  

(2011/12/06 19:07), markus heiler wrote:

Issue #5716 has been reported by markus heiler.

---

Feature #5716: duplicated when clause is ignored -> Report which clause it is specifically.
http://redmine.ruby-lang.org/issues/5716

Author: markus heiler
Status: Open
Priority: Low
Assignee:
Category:
Target version:

In latest Ruby 1.9.3, if you have warnings enabled, you get information like this here:

foobar.rb:24: warning: duplicated when clause is ignored

This error comes from the file:

compile.c

rb_compile_warning(RSTRING_PTR(iseq->filename), iobj->line_no,
"duplicated when clause is ignored");

This is called, it seems, when the prior function fails:

rb_hash_aset(map, obj, INT2FIX(lobj->position - (pos+len)));

As a user of Ruby, the warning should be better.

Rather than:

foobar.rb:24: warning: duplicated when clause is ignored

I would like to see:

foobar.rb:24: warning: duplicated when clause 'foo' is ignored.

This way, I can scan through the file with the case/when structure
and correct this error. But right now, if you have a very long
case/when structure, you have no idea WHICH clause is duplicated.

The warning message just vaguely says that there is, and this is
not very helpful information.

--
// SASADA Koichi at atdot dot net

[shevegen (Robert A. Heiler)]

Hi Koichi Sasada!

I have not tested it yet (will do so at the end of this week),
but I believe it will help me.

Thank you! :)

[ko1 (Koichi Sasada)]

• Status changed from Assigned to Closed
• % Done changed from 0 to 100

This issue was solved with changeset r35277.
markus, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.

---

• compile.c (iseq_set_sequence): show a hint if there are duplicated
  "when" clauses. [ruby-core:41502] [ruby-trunk - Feature #5716]