From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: by sourceware.org (Postfix, from userid 48) id BDC1D3857C50; Thu, 25 Mar 2021 09:22:51 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org BDC1D3857C50 From: "nickpapior at gmail dot com" To: gcc-bugs@gcc.gnu.org Subject: [Bug fortran/99765] New: Explicit dimension size declaration of pointer array allowed Date: Thu, 25 Mar 2021 09:22:51 +0000 X-Bugzilla-Reason: CC X-Bugzilla-Type: new X-Bugzilla-Watch-Reason: None X-Bugzilla-Product: gcc X-Bugzilla-Component: fortran X-Bugzilla-Version: 4.8.4 X-Bugzilla-Keywords: X-Bugzilla-Severity: normal X-Bugzilla-Who: nickpapior at gmail dot com X-Bugzilla-Status: UNCONFIRMED X-Bugzilla-Resolution: X-Bugzilla-Priority: P3 X-Bugzilla-Assigned-To: unassigned at gcc dot gnu.org X-Bugzilla-Target-Milestone: --- X-Bugzilla-Flags: X-Bugzilla-Changed-Fields: bug_id short_desc product version bug_status bug_severity priority component assigned_to reporter target_milestone Message-ID: 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 X-BeenThere: gcc-bugs@gcc.gnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gcc-bugs mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 25 Mar 2021 09:22:51 -0000 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=3D99765 Bug ID: 99765 Summary: Explicit dimension size declaration of pointer array allowed Product: gcc Version: 4.8.4 Status: UNCONFIRMED Severity: normal Priority: P3 Component: fortran Assignee: unassigned at gcc dot gnu.org Reporter: nickpapior at gmail dot com Target Milestone: --- A mishandling of variable declarations Consider this program: program test real, dimension(10), pointer :: a(:) =3D> null() print *, associated(a) allocate(a(2)) print *, size(a) !print *, size(a(1)) ! obviously fails as a(1) is a scalar end program test It is ambiguous to determine the size of a. The programmer may think that a= fter allocation one has 2x10 elements a(1:2)(1:10) however what is happening is = that the dimension(10) attribute is completely ignored. I can't find anywhere in the standard mentioning that this way of definitio= n is wrong, but I think it clearly shouldn't be allowed. I.e. it is unclear whether the user wants a(1:2)(1:10) or a(1:10)(1:2), in = any case neither of the results are achieved. I found this bug in 4.8.4 and also in 9.3.0, so I assume it exists in all in between. A few more cases that resemble this: real, dimension(10), allocatable :: a(:) behaves exactly like with pointers. It is not well-defined and gets to the a(1:2) case. real, dimension(10), allocatable :: a(10) rightfully errors out on compilation with a somewhat unclear error message 3 | real, dimension(10) :: a(10) | 1 Error: Symbol =E2=80=98a=E2=80=99 at (1) already has basic type of REAL=