[Bug fortran/82774] Structure constructor and deferred type parameter character component

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82774

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Priority|P3                          |P4
      Known to fail|                            |8.0

--- Comment #1 from kargl at gcc dot gnu.org ---
A thread in c.l.f has exposed a problem with a structure
constructor and a deferred character components.  Consider
the code


% a.f90
program main
   implicit none
   type stuff
      character(:), allocatable :: key
   end type stuff
   type(stuff) nonsense, total
   nonsense = stuff('Xe')
   total = stuff(nonsense%key)
   if (nonsense%key /= total%key) call abort
   if (len(total%key) /= 2) call abort
end program main

% gfcx -o z a.f90 && ./z
Abort (core dumped)

If the line 

   total = stuff(nonsense%key)

is replaced by 

   total = stuff(trim(nonsense%key))

then the program compiles and runs correctly.
Thus, the reference to nonsense%key is not
being probably evaluated in the original 
program.  This can be seen in the dump file.


  {
    struct stuff stuff.0;
    struct stuff D.3538;

    stuff.0.key = (character(kind=1)[1:0] *) __builtin_malloc (2);
    stuff.0._key_length = 2;
    (void) __builtin_memcpy ((void *) stuff.0.key, (void *) "Xe", 2);
    D.3538 = nonsense;
    nonsense = stuff.0;
    if (D.3538.key != 0B)
      {
        __builtin_free ((void *) D.3538.key);
        D.3538.key = 0B;
      }
  }

  {
    struct stuff stuff.1;
    struct stuff D.3540;

    stuff.1.key = (character(kind=1)[1:0] *) __builtin_malloc (1);
    stuff.1._key_length = 0;
    (void) __builtin_memcpy ((void *) stuff.1.key, (void *) nonsense.key,
(unsigned long) nonsense._key_length);
    D.3540 = total;
    total = stuff.1;
    if (D.3540.key != 0B)
      {
        __builtin_free ((void *) D.3540.key);
        D.3540.key = 0B;
      }
  }

stuff.1 is clearly wrong.