Re: [PATCH] Fortran: procedures with BIND(C) attribute require explicit interface [PR85877]

[Thomas Koenig <tkoenig@netcologne.de>]

Hi Harald,

> the Fortran standard requires an explicit procedure interface in certain
> situations, such as when they have a BIND(C) attribute (F2018:15.4.2.2).
> The attached patch adds a check for this.
> 
> Regtested on x86_64-pc-linux-gnu.  OK for mainline?

While this fixes the ICE, it misses

function f() bind(c)
   f = 42.
end

subroutine p
   bind(c) f     ! { dg-error "must be explicit" }
   x = f()
end

subroutine s
   interface
      function g() bind(c)
      end function g
   end interface
   x = g()
end

where the interface is picked up via a global symbol.  This code
may not be valid; nagfor rejects it, but I cannot find a
constraint at least in the F2022 draft that prohibits it.

Hm... might it be better to check for attr->module_procedure ||
attr->if_source == IFSRC_IFBODY?

Best regards

	Thomas