[Bug fortran/113254] Option -fallow-invalid-boz does not help with sample code

[kargl at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113254

kargl at gcc dot gnu.org changed:

           What    |Removed                     |Added
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                 CC|                            |kargl at gcc dot gnu.org
           Priority|P3                          |P4

--- Comment #1 from kargl at gcc dot gnu.org ---
-fallow-invalid-boz is not a panacea for invalid Fortran.

F2018 has

   F2018:C7110 (R770) If type-spec is omitted, each ac-value expression
   in the array-constructor shall have the same declared type and kind
   type parameters.

   F2018:C7111 (R770) If type-spec specifies an intrinsic type, each ac-value
   expression in the array-constructor shall be of an intrinsic type that
   is in type conformance with a variable of type type-spec as specified in
   Table 10.8.

As a BOZ is typeless, it therefore cannot be in an array constructor.
Even if you had added a type-spec such as '[integer :: ...]'.

F2023 does allow a BOZ in an array constructor, with the following constraints:

   F2023:C7126 If an ac-value is a boz-literal-constant, type-spec shall
   appear and shall specify type integer or real.

   F2023:C7127 If an ac-value is a boz-literal-constant and type-spec
   specifies type real, the boz-literal-constant shall be a valid internal
   representation for the specified kind of real.

Your code lacks a type-spec, so C7126 kicks in.  Even with a type-spec,
as this is a new F2023 feature, gfortran does not currently support a BOZ
in an array-constructor.

Adding this capability would be a good introduction to contributing to
gfortran development.