From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-bugzilla@gcc.gnu.org>
Received: by sourceware.org (Postfix, from userid 48)
	id AC9A93858C66; Sun, 28 May 2023 04:15:26 +0000 (GMT)
DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org AC9A93858C66
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gcc.gnu.org;
	s=default; t=1685247326;
	bh=zv6doPX55N1jVuBbvNzgYFb1zQXK/AM/lmtvAmP29H0=;
	h=From:To:Subject:Date:In-Reply-To:References:From;
	b=gDokwxmTkI/mLADHreN3VPDsPL7gEQIhavw8gjFhuEB2ks0ihsKvM4LLa2BC97zol
	 TvCxdy1H0w16FB5CWk7VfJ4hn/RvwShbmkekwqgiVA1euG6MrGguk/7kjwYahtkYzs
	 QSggD5I6EE9DPSPfWLaKPcK576xpN9A8LFNGCe1E=
From: "kargl at gcc dot gnu.org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug fortran/109512] accepts implicit dummy procedure even with
 "implicit none (external)"
Date: Sun, 28 May 2023 04:15:25 +0000
X-Bugzilla-Reason: CC
X-Bugzilla-Type: changed
X-Bugzilla-Watch-Reason: None
X-Bugzilla-Product: gcc
X-Bugzilla-Component: fortran
X-Bugzilla-Version: 12.2.0
X-Bugzilla-Keywords: 
X-Bugzilla-Severity: normal
X-Bugzilla-Who: kargl at gcc dot gnu.org
X-Bugzilla-Status: NEW
X-Bugzilla-Resolution: 
X-Bugzilla-Priority: P4
X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org
X-Bugzilla-Target-Milestone: ---
X-Bugzilla-Flags: 
X-Bugzilla-Changed-Fields: 
Message-ID: <bug-109512-4-UH3fn4FJQl@http.gcc.gnu.org/bugzilla/>
In-Reply-To: <bug-109512-4@http.gcc.gnu.org/bugzilla/>
References: <bug-109512-4@http.gcc.gnu.org/bugzilla/>
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: quoted-printable
X-Bugzilla-URL: http://gcc.gnu.org/bugzilla/
Auto-Submitted: auto-generated
MIME-Version: 1.0
List-Id: <gcc-bugs.sourceware.org>

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D109512

--- Comment #2 from kargl at gcc dot gnu.org ---
This patch catches the need for an external attribute.

diff --git a/gcc/fortran/resolve.cc b/gcc/fortran/resolve.cc
index 6e42397c2ea..1e19712b413 100644
--- a/gcc/fortran/resolve.cc
+++ b/gcc/fortran/resolve.cc
@@ -3818,6 +3818,16 @@ resolve_call (gfc_code *c)
   /* Resume assumed_size checking.  */
   need_full_assumed_size--;

+  /* If 'implicit none (external)' and the symbol is a dummy argument,
+     check for an 'external' attribute.  */
+  if (csym->ns->has_implicit_none_export
+      && csym->attr.external =3D=3D 0 && csym->attr.dummy =3D=3D 1)
+    {
+      gfc_error ("Dummy procedure %qs at %C requires an EXTERNAL attribute=
",
+                csym->name);
+      return false;
+    }
+
   /* If external, check for usage.  */
   if (csym && is_external_proc (csym))
     resolve_global_procedure (csym, &c->loc, 1);

A dejagnu-ified testcase.

! { dg-do compile }
subroutine foo(bar)
  implicit none (external)
  call bar(1)        ! { dg-error "requires an EXTERNAL attribute" }
end subroutine foo=