[Bug fortran/61888] New: Wrong results with SIZEOF and assumed-rank arrays

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61888

            Bug ID: 61888
           Summary: Wrong results with SIZEOF and assumed-rank arrays
           Product: gcc
           Version: 4.10.0
            Status: UNCONFIRMED
          Keywords: rejects-valid, wrong-code
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: burnus at gcc dot gnu.org

Per https://gcc.gnu.org/onlinedocs/gfortran/SIZEOF.html, SIZEOF is an inquiry
function (and GNU extension); that's in line with C_SIZEOF. However, the code
doesn't reflect this. That's fixed by:

--- a/gcc/fortran/intrinsic.c
+++ b/gcc/fortran/intrinsic.c
@@ -2768 +2768 @@ add_functions (void)
-  add_sym_1 ("sizeof", GFC_ISYM_SIZEOF, CLASS_IMPURE, ACTUAL_NO, BT_INTEGER,
ii,
+  add_sym_1 ("sizeof", GFC_ISYM_SIZEOF, CLASS_INQUIRY, ACTUAL_NO, BT_INTEGER,
ii,


After doing so, the following test case shows that the size is wrongly
calculated for assumed-rank arrays.

Additionally, one should check whether c_sizeof() should be permitted in this
case. It currently fails with "Error: 'x' argument of 'c_sizeof' intrinsic at
(1) must be an interoperable data entity: Only explicit-size and assumed-size
arrays are interoperable". One has to decipher TS29113 whether those should be
permitted for c_sizeof or not.


use iso_c_binding
implicit none
integer, pointer :: ptr(:)

allocate(ptr(10))
call foo(ptr)
call bar(ptr)

contains

subroutine foo(x)
integer, dimension(:) :: x
print *, sizeof(x) ! Prints EXPECTED: 40
end

subroutine bar(x)
integer, dimension(..) :: x
print *, sizeof(x)  ! WRONG: Prints 4
end
end