From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 7296 invoked by alias); 1 Dec 2017 23:19:52 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Received: (qmail 7286 invoked by uid 89); 1 Dec 2017 23:19:51 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=0.8 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,KAM_STOCKGEN,KB_WAM_FROM_NAME_SINGLEWORD,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 spammy=Hx-languages-length:3691 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 01 Dec 2017 23:19:49 +0000 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id AEF215FD57; Fri, 1 Dec 2017 23:19:48 +0000 (UTC) Received: from [127.0.0.1] (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id 21ECC5D960; Fri, 1 Dec 2017 23:19:42 +0000 (UTC) Subject: Re: [PATCH v5] Add support for the readnever concept To: Sergio Durigan Junior , GDB Patches References: <1467838463-15786-1-git-send-email-brobecker@adacore.com> <20171201221600.22341-1-sergiodj@redhat.com> Cc: Joel Brobecker , Yao Qi , Eli Zaretskii From: Pedro Alves Message-ID: <6ec7b656-9079-5cb2-d2e8-42eaf209887f@redhat.com> Date: Fri, 01 Dec 2017 23:19:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <20171201221600.22341-1-sergiodj@redhat.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2017-12/txt/msg00039.txt.bz2 On 12/01/2017 10:16 PM, Sergio Durigan Junior wrote: > Changes from v4: > > - Cleaned-up the commit message and ChangeLogs. > > - Simplified condition when checking for readnever. Removed "top.h" > from files that didn't need it. > > - Added xref to "-readnever" option (on symbol-file command) pointing > to "--readnever". > > - Merged READNOW_HELP and READNEVER_HELP. > > > The purpose of this concept is to turn the load of debugging > information off, either globally (via the '--readnever' option), or > objfile-specific. The implementation proposed here is an extension of > the patch distributed with Fedora GDB; looking at the Fedora patch > itself and the history, one can see some reasons why it was never > resubmitted: > > - The patch appears to have been introduced as a workaround, at > least initially; > - The patch is far from perfect, as it simply shunts the load of > DWARF debugging information, without really worrying about the > other debug format. > - Who really does non-symbolic debugging anyways? > > One use of this feature is when a user simply wants to do the > following sequence: attach, dump core, detach. Loading the debugging > information in this case is an unnecessary cause of delay. > > This patch expands the version shipped with Fedora GDB in order to > make the feature available for all the debuginfo backends, not only > for DWARF. It also implements a per-objfile flag which can be > activated by using the "-readnever" command when using the > 'add-symbol-file' or 'symbol-file' commands. > > It's also worth mentioning that this patch tests whether GDB correctly > fails to initialize if both '--readnow' and '--readnever' options are > passed. > > Tested on the BuildBot. > > gdb/ChangeLog: > > 2017-12-01 Andrew Cagney > Joel Brobecker > Sergio Durigan Junior > > * NEWS (Changes since GDB 8.0: Mention new '--readnever' > feature. > * coffread.c (coff_symfile_read): Do not map over sections with > 'coff_locate_sections' if readnever is on. > * dwarf2read.c (dwarf2_has_info): Return 0 if > readnever is on. > * elfread.c (elf_symfile_read): Do not map over sections with > 'elf_locate_sections' if readnever is on. > * main.c (validate_readnow_readnever): New function. > (captured_main_1): Add support for --readnever. > (print_gdb_help): Document --readnever. > * objfile-flags.h (enum objfile_flag) : New > flag. > * symfile.c (readnever_symbol_files): New global. > (symbol_file_add_with_addrs): Set 'OBJF_READNEVER' when > 'READNEVER_SYMBOL_FILES' is set. > (validate_readnow_readnever): New function. > (symbol_file_command): Handle '-readnever' option. > Call 'validate_readnow_readnever'. > (add_symbol_file_command): Handle '-readnever' option. > Call 'validate_readnow_readnever'. > (_initialize_symfile): Document new '-readnever' option for > both 'symbol-file' and 'add-symbol-file' commands. > * top.h (readnever_symbol_files): New extern global. > * xcoffread.c (xcoff_initial_scan): Do not read debug > information if readnever is on. > > gdb/doc/ChangeLog: > > 2017-12-01 Andrew Cagney > Joel Brobecker > Sergio Durigan Junior > > * gdb.texinfo (File Options): Document --readnever. > (Commands to Specify Files): Likewise, for 'symbol-file' and > 'add-symbol-file'. > > gdb/testsuite/ChangeLog: > > 2017-12-01 Joel Brobecker > Sergio Durigan Junior > Pedro Alves > > * gdb.base/readnever.c, gdb.base/readnever.exp: New files. OK. Thanks, Pedro Alves