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* [Bug fortran/27589] New: Add compiler flag to check for uninitalized values at runtime
@ 2006-05-13 14:12 tobias dot burnus at physik dot fu-berlin dot de
2006-05-13 14:17 ` [Bug fortran/27589] " tobias dot burnus at physik dot fu-berlin dot de
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: tobias dot burnus at physik dot fu-berlin dot de @ 2006-05-13 14:12 UTC (permalink / raw)
To: gcc-bugs
Currently, gfortran does not seem to have any option to catch uninitialized
variables at run time.
Example (from http://www.polyhedron.com/pb05/linux/diagnose.html):
--------<UNIN1>------------
program uin1
integer x,y,a,b
x=y
a=b
print *,x,a
b=1
end
---------------------------
Other compilers have an options to catch those, e.g.:
ifort64-9.1 -C -check all -warn all,nodec,interfaces -gen_interfaces -traceback
-fpe0 -fpstkchk UIN1.F
./a.out
forrtl: severe (193): Run-Time Check Failure. The variable 'uin1_$Y' is being
used without being defined
NAG: f95 -C=all -C=undefined -info -g -gline UIN1.F
./a.out
Reference to undefined variable Y
Program terminated by fatal error
In UIN1, line 5 of UIN1.F
--
Summary: Add compiler flag to check for uninitalized values at
runtime
Product: gcc
Version: 4.2.0
Status: UNCONFIRMED
Severity: enhancement
Priority: P3
Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tobias dot burnus at physik dot fu-berlin dot de
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
@ 2006-05-13 14:17 ` tobias dot burnus at physik dot fu-berlin dot de
2007-03-22 22:20 ` burnus at gcc dot gnu dot org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: tobias dot burnus at physik dot fu-berlin dot de @ 2006-05-13 14:17 UTC (permalink / raw)
To: gcc-bugs
------- Comment #1 from tobias dot burnus at physik dot fu-berlin dot de 2006-05-13 14:17 -------
Post scriptum: In this case, using -Wuninitialized -O
the compiler detects that the variable is uninitialized; however, for the other
UIN*.FOR examples at polyhdron.com they are not detected at compile-time.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
2006-05-13 14:17 ` [Bug fortran/27589] " tobias dot burnus at physik dot fu-berlin dot de
@ 2007-03-22 22:20 ` burnus at gcc dot gnu dot org
2007-04-18 6:15 ` fxcoudert at gcc dot gnu dot org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: burnus at gcc dot gnu dot org @ 2007-03-22 22:20 UTC (permalink / raw)
To: gcc-bugs
------- Comment #2 from burnus at gcc dot gnu dot org 2007-03-22 22:20 -------
There are actually two run-time tests possible:
a) Check only local variables
(What to do about actual arguments to intent(in) dummy arguments? In the most
cases this is wrong, however foo(read_argument=.false.,arg=uninitialized) is
possible. Better don't check - or only optionally.)
This seems to be done by ifort's -check uninit.
b) Checking all calls, i.e. by passing additional information. This is done by
NAG f95's -C=undefined. This is more comprehensive, but makes procedures
compiled -C=undefined incompatible to those compiled without.
Ideally, gfortran should offer both options.
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
2006-05-13 14:17 ` [Bug fortran/27589] " tobias dot burnus at physik dot fu-berlin dot de
2007-03-22 22:20 ` burnus at gcc dot gnu dot org
@ 2007-04-18 6:15 ` fxcoudert at gcc dot gnu dot org
2007-06-21 16:58 ` burnus at gcc dot gnu dot org
2007-06-22 13:15 ` burnus at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: fxcoudert at gcc dot gnu dot org @ 2007-04-18 6:15 UTC (permalink / raw)
To: gcc-bugs
--
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 |2007-04-18 07:14:46
date| |
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
` (2 preceding siblings ...)
2007-04-18 6:15 ` fxcoudert at gcc dot gnu dot org
@ 2007-06-21 16:58 ` burnus at gcc dot gnu dot org
2007-06-22 13:15 ` burnus at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: burnus at gcc dot gnu dot org @ 2007-06-21 16:58 UTC (permalink / raw)
To: gcc-bugs
------- Comment #3 from burnus at gcc dot gnu dot org 2007-06-21 16:58 -------
Dump a valid program which contains equivalence to show a harder case for the
checks (NAG f95 chokes on it).
program main
implicit none
integer :: i, it, jt
real :: tt
equivalence (jt,tt)
dimension it(10)
do i=1,10
tt=i
print *, tt, jt
it(i)=jt
end do
end
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
` (3 preceding siblings ...)
2007-06-21 16:58 ` burnus at gcc dot gnu dot org
@ 2007-06-22 13:15 ` burnus at gcc dot gnu dot org
4 siblings, 0 replies; 6+ messages in thread
From: burnus at gcc dot gnu dot org @ 2007-06-22 13:15 UTC (permalink / raw)
To: gcc-bugs
------- Comment #4 from burnus at gcc dot gnu dot org 2007-06-22 13:15 -------
(In reply to comment #3)
> Dump a valid program which contains equivalence to show a harder case for the
> checks (NAG f95 chokes on it).
Actually this is wrong according to the Section 16.5.6 of the F2003 standard:
"When a variable of a given type becomes defined, all associated
variables of different type become undefined." There then follows an
exception that allows REAL and COMPLEX to be equivalenced and not
be undefined in this circumstance.
Thus one should check for this as well (but having a note in the documentation
for this case would make sense too.)
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=27589
^ permalink raw reply [flat|nested] 6+ messages in thread
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2021-04-09 17:16 ` [Bug fortran/27589] Add compiler flag to check for uninitalized values at runtime msebor at gcc dot gnu.org
2006-05-13 14:12 [Bug fortran/27589] New: " tobias dot burnus at physik dot fu-berlin dot de
2006-05-13 14:17 ` [Bug fortran/27589] " tobias dot burnus at physik dot fu-berlin dot de
2007-03-22 22:20 ` burnus at gcc dot gnu dot org
2007-04-18 6:15 ` fxcoudert at gcc dot gnu dot org
2007-06-21 16:58 ` burnus at gcc dot gnu dot org
2007-06-22 13:15 ` burnus at gcc dot gnu dot org
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