From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 18050 invoked by alias); 10 May 2018 15:19:48 -0000 Mailing-List: contact fortran-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Post: List-Help: , Sender: fortran-owner@gcc.gnu.org Received: (qmail 17433 invoked by uid 89); 10 May 2018 15:19:47 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-10.9 required=5.0 tests=AWL,BAYES_00,GIT_PATCH_2,GIT_PATCH_3,KAM_SHORT,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=int*, UD:html,v, Sounds, rcs X-Spam-User: qpsmtpd, 2 recipients X-HELO: mo4-p01-ob.smtp.rzone.de Received: from mo4-p01-ob.smtp.rzone.de (HELO mo4-p01-ob.smtp.rzone.de) (85.215.255.54) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Thu, 10 May 2018 15:19:45 +0000 X-RZG-AUTH: ":OGckYUunfvGNVUL0FlRnC4eRM+bOwx0tUtYTrJ/xeZX+ZVZvrbiROUdgPG6Qd0k=" X-RZG-CLASS-ID: mo00 Received: from [192.168.178.68] by smtp.strato.de (RZmta 43.8 DYNA|AUTH) with ESMTPSA id e0b03cu4AFJePAz (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (curve secp521r1 with 521 ECDH bits, eq. 15360 bits RSA)) (Client did not present a certificate); Thu, 10 May 2018 17:19:40 +0200 (CEST) Subject: Re: Document PR 84073 change in /gcc-8/porting_to.html To: Jonathan Wakely , "fortran@gcc.gnu.org" Cc: gcc-patches References: <20180510103333.GV20930@redhat.com> From: =?UTF-8?Q?Thomas_K=c3=b6nig?= Message-ID: <53847172-a278-2605-7f7c-05dd6d79dc45@tkoenig.net> Date: Thu, 10 May 2018 15:19:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/mixed; boundary="------------2AA9F376044E7294BF434378" X-SW-Source: 2018-05/txt/msg00029.txt.bz2 This is a multi-part message in MIME format. --------------2AA9F376044E7294BF434378 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Content-length: 597 Am 10.05.2018 um 14:20 schrieb Thomas Koenig: > Am 10.05.2018 um 12:33 schrieb Jonathan Wakely: >> Should the fix for PR 84073 be documented, so that users whose code is >> now rejected understand why, and how to fix it? >> >> https://gcc.gnu.org/bugzilla/show_bug.cgi?id=84073 >> https://gcc.gnu.org/gcc-8/porting_to.html#fortran > > Sounds like a good idea. > > Since I introduced this, I'll do it within a few days (unless, of > course, somebody beats me to it, which I won't mind :-) OK, not a few days, but a few hours :-) Here is the diff. OK to commit to gcc-docs? Regards Thomas --------------2AA9F376044E7294BF434378 Content-Type: text/x-patch; name="porting.diff" Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename="porting.diff" Content-length: 1159 Index: porting_to.html =================================================================== RCS file: /cvs/gcc/wwwdocs/htdocs/gcc-8/porting_to.html,v retrieving revision 1.6 diff -u -r1.6 porting_to.html --- porting_to.html 4 May 2018 06:35:39 -0000 1.6 +++ porting_to.html 10 May 2018 15:16:57 -0000 @@ -196,7 +196,31 @@ void foo_ (char*, int*, fortran_charlen_t); +

+ Versions of gfortran prior to 8.1 wrongly accepted CHARACTER + variables with a length type parameter other than one as C + interoperable. For example, the code + 


+  module mod
+    use iso_c_binding
+    type, bind(C) :: a
+      character(len=2,kind=c_char) :: b ! Wrong
+    end type a
+    character(len=2), bind(C) :: c ! Also wrong
+  end module mod
+
+ was accepted. To achieve similar functionality, an array of + LEN=1 characters can be used, for example + 

+  module mod
+    use iso_c_binding
+    type, bind(C) :: a
+      character(kind=c_char) :: b(2)
+    end type a
+    character(kind=c_char), bind(C) :: c(2)
+  end module mod
+
+

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