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* [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning
@ 2007-04-24 18:56 burnus at gcc dot gnu dot org
2007-04-24 19:06 ` [Bug middle-end/31688] " pinskia at gcc dot gnu dot org
` (6 more replies)
0 siblings, 7 replies; 8+ messages in thread
From: burnus at gcc dot gnu dot org @ 2007-04-24 18:56 UTC (permalink / raw)
To: gcc-bugs
[Based on PR 31683]
Compiling the following program with "gfortran -O -Wall" gives the bogus
warning:
foo2.f90:4: warning: 'offset.7' may be used uninitialized in this function
foo2.f90:4: warning: 'stride.6' may be used uninitialized in this function
foo2.f90:4: warning: 'pab.0' may be used uninitialized in this function
However, this part of code is not reachable if uninitialized.
The code is essentially:
int offset.7;
if(pab != 0B)
offset.7 = -stride.6;
if (pab == 0B) return;
*force_a = (*pab.0)[offset.7]
Full Fortran source:
MODULE test
IMPLICIT NONE
CONTAINS
SUBROUTINE overlap(s, lds, pab, force_a)
INTEGER, INTENT(IN) :: lds
REAL, DIMENSION(lds, lds, *), INTENT(INOUT) :: s
REAL, DIMENSION(:), INTENT(IN), OPTIONAL :: pab
REAL, INTENT(OUT) :: force_a
if(.not.present(pab)) return
force_a = pab(1)*s(1,1,1)
END SUBROUTINE
END MODULE test
--
Summary: Bogus "may be used uninitialized" warning
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Keywords: diagnostic
Severity: normal
Priority: P3
Component: middle-end
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: burnus at gcc dot gnu dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug middle-end/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
@ 2007-04-24 19:06 ` pinskia at gcc dot gnu dot org
2007-06-20 15:20 ` jv244 at cam dot ac dot uk
` (5 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: pinskia at gcc dot gnu dot org @ 2007-04-24 19:06 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from pinskia at gcc dot gnu dot org 2007-04-24 20:05 -------
This is really the oldest uninitialized variable warning bug out there. PR
5035.
*** This bug has been marked as a duplicate of 5035 ***
--
pinskia at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug middle-end/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
2007-04-24 19:06 ` [Bug middle-end/31688] " pinskia at gcc dot gnu dot org
@ 2007-06-20 15:20 ` jv244 at cam dot ac dot uk
2007-06-20 15:26 ` jv244 at cam dot ac dot uk
` (4 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: jv244 at cam dot ac dot uk @ 2007-06-20 15:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from jv244 at cam dot ac dot uk 2007-06-20 15:20 -------
*** Bug 31683 has been marked as a duplicate of this bug. ***
--
jv244 at cam dot ac dot uk changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jv244 at cam dot ac dot uk
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug middle-end/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
2007-04-24 19:06 ` [Bug middle-end/31688] " pinskia at gcc dot gnu dot org
2007-06-20 15:20 ` jv244 at cam dot ac dot uk
@ 2007-06-20 15:26 ` jv244 at cam dot ac dot uk
2007-06-20 16:25 ` [Bug fortran/31688] " burnus at gcc dot gnu dot org
` (3 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: jv244 at cam dot ac dot uk @ 2007-06-20 15:26 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from jv244 at cam dot ac dot uk 2007-06-20 15:25 -------
Tobias, could you reopen this bug (I can't). This is different from PR 5035.
Whereas PR 5035 warns about variables present in the users code, these warnings
come from frontend generated variables (i.e. offset.7 is nowhere present in the
users code). These warnings are thus needlessly confusing and supposedly can be
easily supressed by giving them proper attributes in the fronted.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug fortran/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
` (2 preceding siblings ...)
2007-06-20 15:26 ` jv244 at cam dot ac dot uk
@ 2007-06-20 16:25 ` burnus at gcc dot gnu dot org
2007-07-03 10:36 ` fxcoudert at gcc dot gnu dot org
` (2 subsequent siblings)
6 siblings, 0 replies; 8+ messages in thread
From: burnus at gcc dot gnu dot org @ 2007-06-20 16:25 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from burnus at gcc dot gnu dot org 2007-06-20 16:25 -------
> Tobias, could you reopen this bug (I can't). This is different from PR 5035.
> Whereas PR 5035 warns about variables present in the users code, these warnings
> come from frontend generated variables
Well, for the middle end it is all the same.
> These warnings are thus needlessly confusing and supposedly can be
> easily supressed by giving them proper attributes in the fronted.
I don't know how one should properly handle these in the front end (without
unneeded initialization of variables), but I reopened the bug and moved it to
the Fortran front end.
--
burnus at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|RESOLVED |UNCONFIRMED
Component|middle-end |fortran
Resolution|DUPLICATE |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug fortran/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
` (3 preceding siblings ...)
2007-06-20 16:25 ` [Bug fortran/31688] " burnus at gcc dot gnu dot org
@ 2007-07-03 10:36 ` fxcoudert at gcc dot gnu dot org
2007-07-03 10:37 ` fxcoudert at gcc dot gnu dot org
2007-07-04 7:44 ` fxcoudert at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: fxcoudert at gcc dot gnu dot org @ 2007-07-03 10:36 UTC (permalink / raw)
To: gcc-bugs
------- Comment #5 from fxcoudert at gcc dot gnu dot org 2007-07-03 10:36 -------
(In reply to comment #4)
> I don't know how one should properly handle these in the front end (without
> unneeded initialization of variables), but I reopened the bug and moved it to
> the Fortran front end.
They need to be marked with TREE_NO_WARNING. I did that once, but never came
close to submitting the patch. I'll take care of this.
--
fxcoudert 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 |2007-07-03 10:36:33
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug fortran/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
` (4 preceding siblings ...)
2007-07-03 10:36 ` fxcoudert at gcc dot gnu dot org
@ 2007-07-03 10:37 ` fxcoudert at gcc dot gnu dot org
2007-07-04 7:44 ` fxcoudert at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: fxcoudert at gcc dot gnu dot org @ 2007-07-03 10:37 UTC (permalink / raw)
To: gcc-bugs
--
fxcoudert at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
AssignedTo|unassigned at gcc dot gnu |fxcoudert at gcc dot gnu dot
|dot org |org
Status|NEW |ASSIGNED
Last reconfirmed|2007-07-03 10:36:33 |2007-07-03 10:37:00
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
* [Bug fortran/31688] Bogus "may be used uninitialized" warning
2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
` (5 preceding siblings ...)
2007-07-03 10:37 ` fxcoudert at gcc dot gnu dot org
@ 2007-07-04 7:44 ` fxcoudert at gcc dot gnu dot org
6 siblings, 0 replies; 8+ messages in thread
From: fxcoudert at gcc dot gnu dot org @ 2007-07-04 7:44 UTC (permalink / raw)
To: gcc-bugs
------- Comment #6 from fxcoudert at gcc dot gnu dot org 2007-07-04 07:43 -------
*** This bug has been marked as a duplicate of 29459 ***
--
fxcoudert at gcc dot gnu dot org changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution| |DUPLICATE
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31688
^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2007-07-04 7:44 UTC | newest]
Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed)
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2007-04-24 18:56 [Bug middle-end/31688] New: Bogus "may be used uninitialized" warning burnus at gcc dot gnu dot org
2007-04-24 19:06 ` [Bug middle-end/31688] " pinskia at gcc dot gnu dot org
2007-06-20 15:20 ` jv244 at cam dot ac dot uk
2007-06-20 15:26 ` jv244 at cam dot ac dot uk
2007-06-20 16:25 ` [Bug fortran/31688] " burnus at gcc dot gnu dot org
2007-07-03 10:36 ` fxcoudert at gcc dot gnu dot org
2007-07-03 10:37 ` fxcoudert at gcc dot gnu dot org
2007-07-04 7:44 ` fxcoudert at gcc dot gnu dot org
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