[RFC] Question on gfortran extension

[Jerry DeLisle]

Hi all,

In working on PR24978 I am looking at several test cases.  Currently the 
following test case is accepted by gfortran as an extension:

integer :: a
data a /5/
data a /8/
print '(3i6)', a
end

The result is that the variable 'a' is assigned the value 5 because that data 
statement is the last to be resolved even though intuitively one might think the 
last data statement ought to take effect. (Resolution occurs in reverse 
statement order)

This extension really goes against the F95 Standard which does not allow 
duplicate initialization.  It is my opinion that this is a dangerous extension. 
  As implemented now, it only warns if one specifies -pedantic and errors if 
given -std=f95 or -std=f2003.  This can leave users open to inadvertent 
duplicate initialization if they do not use the options.

I am wondering if we should keep this extension at all and if so should we at 
least warn as default and error on -pedantic and/or -std=fxx?

Also, if we do keep this extension, should we keep the assignment given in the 
last data statement rather than the first?

Regards,

Jerry