[Patch, fortran] PR51976 - [F2003] Support deferred-length character components of derived types (allocatable string length)

[Steve Kargl]

On Sun, Mar 09, 2014 at 08:38:28AM -0700, W Spector wrote:
> 
> 3.) My example in comment #12 appears to work fine.  However when 
> running the example under valgrind, memory leaks are indicated.  I cut 
> the example down quite a bit, and it seems that there are leaks 
> regardless of whether derived types are used or not.  So this isn't a 
> regression due to this patch, but something that has been around for a 
> while:
> 
> wws@w6ws-4:~/fortran/strings$ cat deflen_test5.f90
> program strings
>    implicit none
> 
>    character(:), allocatable :: string
> 
>    string = "first string"
>    print *, string
>    string = "second string"
>    print *, string
>    string = "3rd string"
>    print *, string

     deallocate(string)  ! Fix valgrind

> end program
> 
> wws@w6ws-4:~/fortran/strings$ valgrind --leak-check=full a.out

(elided)

>   first string
>   second string
>   3rd string
> ==3153==
> ==3153== HEAP SUMMARY:
> ==3153==     in use at exit: 10 bytes in 1 blocks
> ==3153==   total heap usage: 24 allocs, 23 frees, 11,851 bytes allocated
> ==3153==
> ==3153== 10 bytes in 1 blocks are definitely lost in loss record 1 of 1
> ==3153==    at 0x4C2B4F0: realloc (in 
> /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
> ==3153==    by 0x400B0E: MAIN__ (in /home/wws/fortran/strings/a.out)
> ==3153==    by 0x400C12: main (in /home/wws/fortran/strings/a.out)
> ==3153==
> ==3153== LEAK SUMMARY:
> ==3153==    definitely lost: 10 bytes in 1 blocks
> ==3153==    indirectly lost: 0 bytes in 0 blocks
> ==3153==      possibly lost: 0 bytes in 0 blocks
> ==3153==    still reachable: 0 bytes in 0 blocks
> ==3153==         suppressed: 0 bytes in 0 blocks
> ==3153==
> ==3153== For counts of detected and suppressed errors, rerun with: -v
> ==3153== ERROR SUMMARY: 1 errors from 1 contexts (suppressed: 2 from 2)

% gfc4x -o z b.f90
% valgrind ./z
(elided)
 first string
 second string
 3rd string
==14338== 
==14338== HEAP SUMMARY:
==14338==     in use at exit: 0 bytes in 0 blocks
==14338==   total heap usage: 20 allocs, 20 frees, 2,839 bytes allocated
==14338== 
==14338== All heap blocks were freed -- no leaks are possible
==14338== 
==14338== For counts of detected and suppressed errors, rerun with: -v
==14338== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)

-- 
Steve