[Bug fortran/103312] [11/12/13/14 Regression] ICE in gfc_find_component since r9-1098-g3cf89a7b992d483e

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

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103312

Paul Thomas <pault at gcc dot gnu.org> changed:

           What    |Removed                     |Added
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                 CC|                            |pault at gcc dot gnu.org
           Assignee|unassigned at gcc dot gnu.org      |pault at gcc dot gnu.org

--- Comment #6 from Paul Thomas <pault at gcc dot gnu.org> ---
Created attachment 57969
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57969&action=edit
Partial fix for the PR

The supplied testcase generates completely blank derived type symbols for the
_vptr component of 'this' in 'func'. The chunk in resolve.cc fixes that.

The rest of the patch allows the full testcase below to blast through to
translation, where it dies in trans-decl.cc - again with blanks symbols in the
default initializer this time.

Of the compilers to which I have access, only NAG succeeds with the full
testcase. If this%size() is replaced with a constant expression or an integer
dummy argument, all compilers succeed, including current versions of gfortran.

I have taken it but need to get on with daytime work for a few days.

Paul

module example

  type, abstract :: foo
    integer :: i
  contains
    procedure(foo_size), deferred :: size
    procedure(foo_func), deferred :: func
  end type

  interface
    function foo_func (this) result (string)
      import :: foo
      class(foo) :: this
      character(this%size()) :: string
    end function
    pure integer function foo_size (this)
      import foo
      class(foo), intent(in) :: this
    end function
  end interface

end module

module extension
  use example
  implicit none
  type, extends(foo) :: bar
!    integer :: i
  contains
    procedure :: size
    procedure :: func
  end type

contains
    pure integer function size (this)
      class(bar), intent(in) :: this
      size = this%i
    end function
    function func (this) result (string)
      class(bar) :: this
      character(this%size()) :: string
      string = repeat ("x", len (string))
    end function

end module

  use example
  use extension
  type(bar) :: a
  a%i = 5
  print *, a%func()
end