[Bug fortran/128042] valgrind error in gfc_encode_character(int, unsigned long, unsigned int const*, unsigned char*, unsigned long) (target-memory.cc:255)

[anlauf at gcc dot gnu.org via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=128042

--- Comment #4 from Harald Anlauf <anlauf at gcc dot gnu.org> ---
Somewhat reduced testcase:

program test
  implicit none
  type tag3
     character(4) :: c3(2) = ""
  end type tag3
  type tag2
     type(tag3)   :: t3(2)
  end type tag2

! type(tag2), parameter   :: x = tag2(tag3(['opqr','strv'])) ! fails too
  type(tag2), parameter   :: x = tag2(tag3( 'opqr'        ))
  type(tag2)              :: y = x
  integer,    parameter   :: n = storage_size (x) / 8
  integer                 :: k = n
  character, dimension(n) :: zz1, zz2, zz3, zz4

  zz1 = transfer(x,'*',k)    ! not simplified (k is variable)
  zz2 = transfer(y,'*',k)
  zz3 = transfer(y,'*',n)    ! not simplified (ytag is variable)
  zz4 = transfer(x,'*',n)    ! <<< bad simplification
  print *, zz1
  print *, zz2
  print *, zz3
  print *, zz4
end

This prints:

 opqropqropqropqr
 opqropqropqropqr
 opqropqropqropqr
 opqr^@^@^@^@^@^@^@^@^@^@^@^@

The simplification of TRANSFER fails for (nested?) derived types.