[Bug fortran/101735] New: Type parameter inquiries for substrings are rejected

[Bug fortran/101735] New: Type parameter inquiries for substrings are rejected

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101735

            Bug ID: 101735
           Summary: Type parameter inquiries for substrings are rejected
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: fortran
          Assignee: unassigned at gcc dot gnu.org
          Reporter: anlauf at gcc dot gnu.org
  Target Milestone: ---

As noted by Tobias Burnus in pr100950, type parameter inquiries
(see e.g. F2018:9.4.5) are not recognized for substrings.

character(len=5)   :: str
integer, parameter :: j = str% kind      ! accepted (ok)
integer, parameter :: k = str% len       ! accepted (ok)
integer, parameter :: l = str(1:3)% len  ! not accepted
integer, parameter :: m = str(1:3)% kind ! not accepted
end

gives:

pr100950-inq.f90:4:25:

    4 | integer, parameter :: l = str(1:3)% len  ! not accepted
      |                         1
Error: Parameter 'str' at (1) has not been declared or is a variable, which
does not reduce to a constant expression
pr100950-inq.f90:5:25:

    5 | integer, parameter :: m = str(1:3)% kind ! not accepted
      |                         1
Error: Parameter 'str' at (1) has not been declared or is a variable, which
does not reduce to a constant expression

[Bug fortran/101735] Type parameter inquiries for substrings are rejected

[anlauf at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101735

anlauf at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Last reconfirmed|                            |2021-08-02
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from anlauf at gcc dot gnu.org ---
Furthermore:

character(len=5) :: str
print *, str% len      ! accepted (ok)
print *, str(1:3)% len ! syntax error!?
end

produces:

pr101735-tb.f90:3:18:

    3 | print *, str(1:3)% len ! syntax error!?
      |                  1
Error: Syntax error in PRINT statement at (1)

[Bug fortran/101735] Type parameter inquiries for substrings are rejected

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101735

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |kargl at gcc dot gnu.org

--- Comment #2 from kargl at gcc dot gnu.org ---
(In reply to anlauf from comment #1)
> Furthermore:
> 
> character(len=5) :: str
> print *, str% len      ! accepted (ok)
> print *, str(1:3)% len ! syntax error!?
> end
> 
> produces:
> 
> pr101735-tb.f90:3:18:
> 
>     3 | print *, str(1:3)% len ! syntax error!?
>       |                  1
> Error: Syntax error in PRINT statement at (1)

I think it is a bug in gfortran.  F2018 shows designator % type-param-name
with blanks around %.  For fixed-form source code, blanks are irrelevant.
For free-form source code, 6.3.2.2 has "Blanks may be inserted freely between
tokens to improve readability; for example, blanks may occur between the
tokens that form a complex literal constant."

So, I would think we treat % as a token.

[Bug fortran/101735] Type parameter inquiries for substrings are rejected

[burnus at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101735

Tobias Burnus <burnus at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |burnus at gcc dot gnu.org
           Keywords|                            |rejects-valid

--- Comment #3 from Tobias Burnus <burnus at gcc dot gnu.org> ---
Additional example – same general issue, different error message:

character(len=5) :: str2(4)
type t
   character(len=5) :: str(4)
end type t
type(t) :: var
integer :: x, y 

x = var%str(:)(1:1)%len  ! Bogus: 'Invalid character in name'
y = str2(:)(1:1)%len     ! Bogus: 'Invalid character in name'

Plus: same issue with:  % kind