X-Recipient: archive-cygwin@delorie.com X-SWARE-Spam-Status: No, hits=-3.1 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_LOW,SPF_PASS X-Spam-Check-By: sourceware.org Message-ID: <4989511F.4040200@cwilson.fastmail.fm> Date: Wed, 04 Feb 2009 03:26:07 -0500 From: Charles Wilson User-Agent: Mozilla/5.0 (Windows; U; Windows NT 6.0; en-US; rv:1.8.1.19) Gecko/20081209 Thunderbird/2.0.0.19 Mnenhy/0.7.5.666 MIME-Version: 1.0 To: cygwin@cygwin.com Subject: Re: "Incompatible" typedefs References: <1233680809.17414.1298297091@webmail.messagingengine.com> <20090203171556.GB12192@ednor.casa.cgf.cx> In-Reply-To: <20090203171556.GB12192@ednor.casa.cgf.cx> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Mailing-List: contact cygwin-help@cygwin.com; run by ezmlm List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: cygwin-owner@cygwin.com Mail-Followup-To: cygwin@cygwin.com Delivered-To: mailing list cygwin@cygwin.com Christopher Faylor wrote: > On Tue, Feb 03, 2009 at 12:06:49PM -0500, Charles Wilson wrote: >> I ran across an oddity in the cygwin headers today. > > This boils down to "What does linux do?". If we are doing something > different then PTC. Errr, it's a little weird. On linux, I have: From typedef unsigned int u_int8_t __attribute__ ((__mode__ (__QI__))); typedef unsigned int u_int16_t __attribute__ ((__mode__ (__HI__))); typedef unsigned int u_int32_t __attribute__ ((__mode__ (__SI__))); typedef unsigned int u_int64_t __attribute__ ((__mode__ (__DI__))); From typedef unsigned char uint8_t; typedef unsigned short int uint16_t; typedef unsigned int uint32_t; From typedef signed char __int8_t; typedef unsigned char __uint8_t; typedef signed short int __int16_t; typedef unsigned short int __uint16_t; typedef signed int __int32_t; typedef unsigned int __uint32_t; So it looks like everything is defined in terms of ANSI C types (int, char, etc) without the intermediation that cygwin's headers use. So, all of the [__]u[_]int32_t types are all 'unsigned int'. I'm guessing that "__attribute__ ((__mode__ (__SI__)))" doesn't make u_int32_t different than uint32_t. But apparently there is some heavy duty compiler magic happening, because I would have thought that these two: typedef unsigned int u_int16_t __attribute__ ((__mode__ (__HI__))); typedef unsigned short int uint16_t; are very different. But they are not (in that a variation of my test case I posted earlier, emits no warnings with these two types). I'm not sure what useful conclusions we can draw from looking at how linux does it, Or maybe I just need some sleep. -- Chuck -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/