[Bug fortran/20520] New: allocatable arrays may be used without being allocated

2005-03-17 Thread ebertakis at gmail dot com 
The compiler does not display an error message when in a source file 
allocatable arrays are being used without having been allocated beforehand. For 
example, the following code is erroneous, but nevertheless the compiler will 
compile (and build) it silently:

real,allocatable:: a(:),b(:)

a(1)=2*b(1)

end

Of course, the executable produced will collapse when run.

The gfortran compiler used was the standalone package for Windows (downloaded 
as a zip archive).

-- 
   Summary: allocatable arrays may be used without being allocated
   Product: gcc
   Version: 4.0.0
Status: UNCONFIRMED
  Severity: normal
  Priority: P2
 Component: fortran
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: ebertakis at gmail dot com
CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20520

[Bug fortran/20520] allocatable arrays used without being allocated without a warning

2005-03-17 Thread ebertakis at gmail dot com 

--- Additional Comments From ebertakis at gmail dot com  2005-03-17 19:07 
---
(In reply to comment #1)

I tried it in Compaq Visual Fortran Professional Edition 6.5 and indeed the
compiler accepts the code. The debugger though will display an error message
indicating the line "a(1)=2*b(1)" and saying that the array bounds were 
exceeded.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20520

[Bug fortran/20520] allocatable arrays used uninitialized without a warning

2005-03-20 Thread ebertakis at gmail dot com 

--- Additional Comments From ebertakis at gmail dot com  2005-03-20 19:22 
---
(In reply to comment #4)
This case is slightly different. The compiler just warns you that you are using
variable x before its value have been defined. Many programmers (that have bad
programming habits :-) probably that includes myself!) take for granted that
variables have an initial value equal to 0 once their memory space is reserved
upon definition as e.g. real. That is not always true and is heavily dependant
on the compiler that is used. Many compilers fill the variables with garbage
when they are first declared. See also the Fortran FAQ (paragraph 3.2.3):
http://www.faqs.org/faqs/fortran-faq/
That is why you got that warning. I believe it is not related to the array 
usage.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=20520