This is the mail archive of the systemtap@sourceware.org mailing list for the systemtap project.


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]
Other format: [Raw text]

Re: semantic error: multiple addresses for ...


> For more history, see commit 897820ca and PR1306.
> 
> http://sourceware.org/git/gitweb.cgi?p=systemtap.git;h=897820ca
> http://sourceware.org/bugzilla/show_bug.cgi?id=1306

Thanks for these pointers.

> In comment #2, some guy named Roland indicates that this may be a
> non-trivial problem in the general case...

Indeed it is.  The question is how best to resolve it.  
IMHO the current situation is not good.

Off hand, I see two potential approaches:

1. Pay attention to is_stmt.
   I mentioned this earlier.  To consider this, we'd really need to find
   some cases where the current code legitimately complains as in PR1306,
   and check whether the is_stmt flags in that DWARF info are useful.

2. Apply the current rule only when there are multiple hits in the same scope.
   This seems probably safer than relying on is_stmt, though it's not clear.
   This should fix the case I just reported, and ones like it, where the
   multiple hits are in entirely different instances of the same source code.

   This too could possibly go wrong due to unusual optimization choices,
   but it seems far less likely.


Thanks,
Roland


Index Nav: [Date Index] [Subject Index] [Author Index] [Thread Index]
Message Nav: [Date Prev] [Date Next] [Thread Prev] [Thread Next]