On Tue, Jan 23, 2018 at 6:33 PM, Thomas Koenig <tkoe...@netcologne.de> wrote:
> Hi Janne,
>
>> When associating a variable of type character, if the length of the
>> target isn't known, set it to zero rather than leaving it unset. This
>> is not a complete fix for making associate of characters work
>> properly, but papers over an ICE in the middle-end. See PR 83344 for
>> more details.
>>
>> Regtested on x86_64-pc-linux-gnu, Ok for trunk?
>
>
> Does the code which is accepted then execute correctly?
Hmm, prompted by your question I did some investigating, and I present
to you evidence of GFortran being a quantum mechanical compiler
(spooky action at a distance!): Consider the slightly fleshed out
testcase from PR 83975:
program foo
call s("foo")
contains
subroutine s(x)
character(*) :: x
print *, "X:", x, ":ENDX"
print *, "len(x): ", len(x)
! associate (y => x)
! print *, "Y:", y, ":ENDY"
! print *, "len(y): ", len(y)
! end associate
end subroutine s
end program foo
With the associate stuff commented out, it's fairly bog-standard
stuff, and the output is the expected:
X:foo:ENDX
len(x): 3
Now, incorporating the commented out associate block, and the result is:
X::ENDX
len(x): 0
Y::ENDY
len(y): 0
So the associate construct manages to somehow break the variable X in
the outer scope!
--
Janne Blomqvist
