From owner-svn-src-head@freebsd.org Fri Mar 15 18:43:45 2019 Return-Path: Delivered-To: svn-src-head@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2610:1c1:1:606c::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id B2BCA152A106; Fri, 15 Mar 2019 18:43:44 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from smtp.freebsd.org (smtp.freebsd.org [96.47.72.83]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) server-signature RSA-PSS (4096 bits) client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "smtp.freebsd.org", Issuer "Let's Encrypt Authority X3" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 4C3F575FA5; Fri, 15 Mar 2019 18:43:44 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Received: from John-Baldwins-MacBook-Pro-3.local (ralph.baldwin.cx [66.234.199.215]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client did not present a certificate) (Authenticated sender: jhb) by smtp.freebsd.org (Postfix) with ESMTPSA id A27BD1E51C; Fri, 15 Mar 2019 18:43:43 +0000 (UTC) (envelope-from jhb@FreeBSD.org) Subject: Re: svn commit: r345196 - head/sys/sys From: John Baldwin To: Gleb Smirnoff , src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org References: <201903151818.x2FII5Kv085552@repo.freebsd.org> <763f5e3c-38c1-2920-8138-6bae9482ad1f@FreeBSD.org> Openpgp: preference=signencrypt Autocrypt: addr=jhb@FreeBSD.org; keydata= mQGiBETQ+XcRBADMFybiq69u+fJRy/0wzqTNS8jFfWaBTs5/OfcV7wWezVmf9sgwn8TW0Dk0 c9MBl0pz+H01dA2ZSGZ5fXlmFIsee1WEzqeJzpiwd/pejPgSzXB9ijbLHZ2/E0jhGBcVy5Yo /Tw5+U/+laeYKu2xb0XPvM0zMNls1ah5OnP9a6Ql6wCgupaoMySb7DXm2LHD1Z9jTsHcAQMD /1jzh2BoHriy/Q2s4KzzjVp/mQO5DSm2z14BvbQRcXU48oAosHA1u3Wrov6LfPY+0U1tG47X 1BGfnQH+rNAaH0livoSBQ0IPI/8WfIW7ub4qV6HYwWKVqkDkqwcpmGNDbz3gfaDht6nsie5Z pcuCcul4M9CW7Md6zzyvktjnbz61BADGDCopfZC4of0Z3Ka0u8Wik6UJOuqShBt1WcFS8ya1 oB4rc4tXfSHyMF63aPUBMxHR5DXeH+EO2edoSwViDMqWk1jTnYza51rbGY+pebLQOVOxAY7k do5Ordl3wklBPMVEPWoZ61SdbcjhHVwaC5zfiskcxj5wwXd2E9qYlBqRg7QeSm9obiBCYWxk d2luIDxqaGJARnJlZUJTRC5vcmc+iGAEExECACAFAkTQ+awCGwMGCwkIBwMCBBUCCAMEFgID AQIeAQIXgAAKCRBy3lIGd+N/BI6RAJ9S97fvbME+3hxzE3JUyUZ6vTewDACdE1stFuSfqMvM jomvZdYxIYyTUpC5Ag0ERND5ghAIAPwsO0B7BL+bz8sLlLoQktGxXwXQfS5cInvL17Dsgnr3 1AKa94j9EnXQyPEj7u0d+LmEe6CGEGDh1OcGFTMVrof2ZzkSy4+FkZwMKJpTiqeaShMh+Goj XlwIMDxyADYvBIg3eN5YdFKaPQpfgSqhT+7El7w+wSZZD8pPQuLAnie5iz9C8iKy4/cMSOrH YUK/tO+Nhw8Jjlw94Ik0T80iEhI2t+XBVjwdfjbq3HrJ0ehqdBwukyeJRYKmbn298KOFQVHO EVbHA4rF/37jzaMadK43FgJ0SAhPPF5l4l89z5oPu0b/+5e2inA3b8J3iGZxywjM+Csq1tqz hltEc7Q+E08AAwUIAL+15XH8bPbjNJdVyg2CMl10JNW2wWg2Q6qdljeaRqeR6zFus7EZTwtX sNzs5bP8y51PSUDJbeiy2RNCNKWFMndM22TZnk3GNG45nQd4OwYK0RZVrikalmJY5Q6m7Z16 4yrZgIXFdKj2t8F+x613/SJW1lIr9/bDp4U9tw0V1g3l2dFtD3p3ZrQ3hpoDtoK70ioIAjjH aIXIAcm3FGZFXy503DOA0KaTWwvOVdYCFLm3zWuSOmrX/GsEc7ovasOWwjPn878qVjbUKWwx Q4QkF4OhUV9zPtf9tDSAZ3x7QSwoKbCoRCZ/xbyTUPyQ1VvNy/mYrBcYlzHodsaqUDjHuW+I SQQYEQIACQUCRND5ggIbDAAKCRBy3lIGd+N/BCO8AJ9j1dWVQWxw/YdTbEyrRKOY8YZNwwCf afMAg8QvmOWnHx3wl8WslCaXaE8= Message-ID: <5d6a44da-7980-e8a1-a41f-2d30e373b3a8@FreeBSD.org> Date: Fri, 15 Mar 2019 11:43:42 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.12; rv:60.0) Gecko/20100101 Thunderbird/60.5.3 MIME-Version: 1.0 In-Reply-To: <763f5e3c-38c1-2920-8138-6bae9482ad1f@FreeBSD.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Rspamd-Queue-Id: 4C3F575FA5 X-Spamd-Bar: ------ Authentication-Results: mx1.freebsd.org X-Spamd-Result: default: False [-6.99 / 15.00]; NEURAL_HAM_MEDIUM(-1.00)[-1.000,0]; NEURAL_HAM_SHORT(-0.99)[-0.993,0]; NEURAL_HAM_LONG(-1.00)[-1.000,0]; REPLY(-4.00)[] X-BeenThere: svn-src-head@freebsd.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: SVN commit messages for the src tree for head/-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 15 Mar 2019 18:43:45 -0000 On 3/15/19 11:28 AM, John Baldwin wrote: > On 3/15/19 11:18 AM, Gleb Smirnoff wrote: >> Author: glebius >> Date: Fri Mar 15 18:18:05 2019 >> New Revision: 345196 >> URL: https://svnweb.freebsd.org/changeset/base/345196 >> >> Log: >> Deanonymize thread and proc state enums, so that a userland app can >> use them without redefining the value names. New clang no longer >> allows to redefine a enum value name to the same value. >> >> Bump __FreeBSD_version, since ports depend on that. >> >> Discussed with: jhb > > Note that devel/mdb from before this commit will no longer work on > kernels built with this commit (so you can't use mdb on a 12.x box > to cross-debug a crash with this change anymore). Similarly, once > mdb is fixed to build with this change, a new mdb built with this > won't work with older kernels. For background, mdb makes "clever" use of CTF debug info. You declare a structure in the debugger (or one of the debugger modules) that contains a subset of the fields of the type from the thing you are debugging. mdb then compares the CTF of the two structures and figures out how to copy the needed fields from the target structure into the smaller one in the debugger module handling endian-ness swaps, integer size differences, etc. However, it requires the types of each field to be identical. The simplest way to do this is to make a copy of the field by literally copying the fields (in this case from sys/proc.h). This meant that mdb had structs like this: typedef struct { ... enum { TDS_INACTIVE = 0, ... } td_state; } mdb_thread_t; clang 8, in its infinite wisdom decided that the existing enum values in conflicted with the ones in mdb_thread_t even though the numerical value of the enumerators was identical. Note that even with this change, the existing code can't be copied verbatim to mdb as using 'enum td_states { TDS_INACTIVE' once again triggers clang 8's hyper-sensitivity. Thus, with clang 8 it is now impossible to copy and paste enum fields from the target structure to the debugger version of the structure if you ever include the original header for some other reason. I consider this to be a compiler bug that it isn't able to understand that 0 == 0. -- John Baldwin