------- Comment #10 from drow at gcc dot gnu dot org 2006-07-21 16:57 -------
(In reply to comment #9)
> Case 1:
> There is no location info for the parameter x because it has been optimized
> away. Change the variable x in main to y to avoid ambiguity, compile with
> -fdump-tree-all, and look at the t27 and t29 dumps. In the t27 dump, the
> variable x is there and assigned to. In the t29 dump, the variable x is
> there,
> but no longer assigned to. Since it is no longer assigned to, we never
> allocate space for it, and hence no location attribute can be emitted. t29 is
> the copyrename dump file. If I compile with -fno-tree-copyrename, then I do
> get a location attribute for the parameter x in the inlined copy of foo. I
> don't think there is any bug here, but if there is, it would be in the tree
> copyrename pass, because there is no longer any useful parameter x when it is
> done.
For the record, I encountered this problem today also (formals with no location
information). Not a single argument had a location. Adding
-fno-tree-copyrename fixed one (of about seven). In this case the variables
are all used, mostly in non-trivial ways. My testcase was eval.c from GDB; the
function evaluate_struct_tuple is inlined and debugging into it is quite hard.
I'm working on improving this in GDB, but I can't improve where the compiler
gives me nothing to work with.
We already know that there are many similar problems in the tree optimizers;
I'm just adding a data point.
--
drow at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever Confirmed|0 |1
Last reconfirmed|0000-00-00 00:00:00 |2006-07-21 16:57:25
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23551
