From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15941 invoked by alias); 18 Jul 2012 22:34:02 -0000 Received: (qmail 15685 invoked by uid 22791); 18 Jul 2012 22:34:00 -0000 X-SWARE-Spam-Status: No, hits=-5.0 required=5.0 tests=AWL,BAYES_00,DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,KHOP_RCVD_TRUST,KHOP_THREADED,RCVD_IN_DNSWL_LOW,RCVD_IN_HOSTKARMA_YE,TW_BJ,TW_JC,TW_YM,T_RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from mail-ee0-f73.google.com (HELO mail-ee0-f73.google.com) (74.125.83.73) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Wed, 18 Jul 2012 22:33:46 +0000 Received: by eeke51 with SMTP id e51so111007eek.0 for ; Wed, 18 Jul 2012 15:33:45 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:content-type:content-transfer-encoding:message-id:date :to:cc:subject:in-reply-to:references:x-mailer:from :x-gm-message-state; bh=tgppR8W4/IRgiv9hzDmQaDgvr5LN8vXUgTVlnZHHw/o=; b=jDWW5/fG64jxcFF3z6jGnfzet17QXalaN4Uh7Q1NaE0xWXhcDs5fP9PayCtfE2Wsg8 7p3UyYaB2uW4uckJdAEuylypXErZ2krdzzTtIwdOs66AdmP+DwXz4N3Cdq+cyg9YT1c8 lEFpm96r6kZxpnAlU1beG77kDvKSceOLal1ne7ROPGnMTj+m5IKFpaRcVWsB8NU0J12O VeCzYpJR3NaBsaR+7gpoOc1KBxJFn+945oeELO6Uh27GFIkmNFWH+Gq+o2XCWXoTHp8N 7piwux1DEkqldJnff8FCc/WOcpzZEdqIrTo1WbMxePkHlJu0yxbO1y6nuDJKtJy6xw3B yiTQ== Received: by 10.180.75.8 with SMTP id y8mr818849wiv.4.1342650825311; Wed, 18 Jul 2012 15:33:45 -0700 (PDT) Received: by 10.180.75.8 with SMTP id y8mr818842wiv.4.1342650825244; Wed, 18 Jul 2012 15:33:45 -0700 (PDT) Received: from hpza9.eem.corp.google.com ([74.125.121.33]) by gmr-mx.google.com with ESMTPS id 46si379830eed.1.2012.07.18.15.33.45 (version=TLSv1/SSLv3 cipher=AES128-SHA); Wed, 18 Jul 2012 15:33:45 -0700 (PDT) Received: from ruffy2.mtv.corp.google.com (ruffy2.mtv.corp.google.com [172.18.110.129]) by hpza9.eem.corp.google.com (Postfix) with ESMTP id DA2EC5C0050; Wed, 18 Jul 2012 15:33:43 -0700 (PDT) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <20487.14790.662664.583456@ruffy2.mtv.corp.google.com> Date: Wed, 18 Jul 2012 22:34:00 -0000 To: Jan Kratochvil Cc: gdb-patches@sourceware.org, eliz@gnu.org Subject: Re: [RFA, doc RFA] New option set use-deprecated-index-sections In-Reply-To: <20120717214257.GA9394@host2.jankratochvil.net> References: <20120717214257.GA9394@host2.jankratochvil.net> From: dje@google.com X-Gm-Message-State: ALoCoQl0STICtWUj9uoIvb4lnXlUqd5ax3ByLBIWsBlFxJzHUvYVROeWOQO1OC0SSmLcbHe18PI1Pj5gaLw+Wvht92YRwQsCPmy/UFiDto+t17kzFAXRNUSZ3kVgdTO296UQJ/ZheO0efJUlf0SFi/nIYJtwEEeL7cZdpr3hX3VYkAdvE6DmO3Qno4hZLuEqUlPTymvD12dF X-IsSubscribed: yes 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 X-SW-Source: 2012-07/txt/msg00308.txt.bz2 Jan Kratochvil writes: > On Tue, 17 Jul 2012 23:23:51 +0200, dje@google.com wrote: > > I was going to wait to apply this until after 7.5, > > but with the new "-iex" option I realize that the new > > "--use-deprecated-index-sections" option could be considered redundant. > > So I'm thinking about deleting that as well, in favor of having just this. > > I would find less GDB options to be good. > > > > +@item set use-deprecated-index-sections > > +@kindex set use-deprecated-index-sections > > +Set this option to control the treatment of deprecated index sections. > > +When @code{on}, index sections are used even if they are deprecated. > > > +When @code{off}, only current versions of index sections are used. > > +The default is @code{off}. > > This is not completely correct: > if (version < 6 && !use_deprecated_index_sections) > if (version > 7) > > So version 6 is not "current" but it is still used even without > -use-deprecated-index-sections. At least gdb doc should be exact IMO. > > It is also questionable if version 6 should be ignored without > -use-deprecated-index-sections. I guess the possible performance regression > (against non-index case) is so rare it was not worth ignoring version 6. How about this? (for cvs head and the 7.5 branch) [This patch needs a slight tweak to apply cleanly to the branch. I'll make the tweak after checking this into head.] P.S. Eli, I need a doc RFA here too. Thanks. 2012-07-18 Doug Evans * NEWS: Document new options "set/show use-deprecated-index-sections", and delete reference to --use-deprecated-index-sections. * symfile.h (use_deprecated_index_sections): Delete. * dwarf2read.c (use_deprecated_index_sections): Make static. (read_index_from_section): Update wording of how to load deprecated index sections. (_initialize_dwarf2_read): New options "set/show use-deprecated-index-sections". * main.c (captured_main): Delete --use-deprecated-index-sections. doc/ * gdb.texinfo (Mode Options): Delete --use-deprecated-index-sections. (Index Files): Document how to control the use of deprecated index sections. (Index Section Format): Replace --use-deprecated-index-sections with "set use-deprecated-index-sections on". Index: NEWS =================================================================== RCS file: /cvs/src/src/gdb/NEWS,v retrieving revision 1.534 diff -u -p -r1.534 NEWS --- NEWS 18 Jul 2012 04:02:10 -0000 1.534 +++ NEWS 18 Jul 2012 22:21:17 -0000 @@ -114,11 +114,13 @@ * The .gdb_index section has been updated to include symbols for inlined functions. GDB will ignore older .gdb_index sections by default, which could cause symbol files to be loaded more slowly - until their .gdb_index sections can be recreated. The new option - --use-deprecated-index-sections will cause GDB to use any older - .gdb_index sections it finds. This will restore performance, but - the ability to set breakpoints on inlined functions will be lost - in symbol files with older .gdb_index sections. + until their .gdb_index sections can be recreated. The new command + "set use-deprecated-index-sections on" will cause GDB to use any older + .gdb_index sections it finds. To control this from the command line + use "-iex 'set use-deprecated-index-sections on'". + This will restore performance, but the ability to set breakpoints on + inlined functions will be lost in symbol files with older .gdb_index + sections. The .gdb_index section has also been updated to record more information about each symbol. This speeds up the "info variables", "info functions" @@ -139,6 +141,10 @@ * New commands + ** "set use-deprecated-index-sections on|off" + "show use-deprecated-index-sections on|off" + Controls the use of deprecated .gdb_index sections. + ** "catch load" and "catch unload" can be used to stop when a shared library is loaded or unloaded, respectively. Index: dwarf2read.c =================================================================== RCS file: /cvs/src/src/gdb/dwarf2read.c,v retrieving revision 1.693 diff -u -p -r1.693 dwarf2read.c --- dwarf2read.c 18 Jul 2012 20:01:27 -0000 1.693 +++ dwarf2read.c 18 Jul 2012 22:21:18 -0000 @@ -85,7 +85,7 @@ static int dwarf2_die_debug = 0; static int check_physname = 0; /* When non-zero, do not reject deprecated .gdb_index sections. */ -int use_deprecated_index_sections = 0; +static int use_deprecated_index_sections = 0; /* When set, the file that we're processing is known to have debugging info for C++ namespaces. GCC 3.3.x did not produce this information, @@ -2611,15 +2611,18 @@ read_index_from_section (struct objfile Versions earlier than 6 did not emit psymbols for inlined functions. Using these files will cause GDB not to be able to set breakpoints on inlined functions by name, so we ignore these - indices unless the --use-deprecated-index-sections command line - option was supplied. */ + indices unless the user has done + "set use-deprecated-index-sections on". */ if (version < 6 && !deprecated_ok) { static int warning_printed = 0; if (!warning_printed) { - warning (_("Skipping deprecated .gdb_index section in %s, pass " - "--use-deprecated-index-sections to use them anyway"), + warning (_("\ +Skipping deprecated .gdb_index section in %s.\n\ +Do \"set use-deprecated-index-sections on\" to use them anyway.\n\ +This can be done from the command line by passing\n\ +`-iex \"set use-deprecated-index-sections on\"' to gdb."), filename); warning_printed = 1; } @@ -19630,6 +19633,17 @@ the demangler."), NULL, show_check_physname, &setdebuglist, &showdebuglist); + add_setshow_boolean_cmd ("use-deprecated-index-sections", + no_class, &use_deprecated_index_sections, _("\ +Set whether to use deprecated gdb_index sections."), _("\ +Show whether to use deprecated gdb_index sections."), _("\ +When enabled .gdb_index sections that have been deprecated are used anyway.\n\ +Normally they are ignored either because of a missing feature or\n\ +performance issue."), + NULL, + NULL, + &setlist, &showlist); + c = add_cmd ("gdb-index", class_files, save_gdb_index_command, _("\ Save a gdb-index file.\n\ Index: main.c =================================================================== RCS file: /cvs/src/src/gdb/main.c,v retrieving revision 1.110 diff -u -p -r1.110 main.c --- main.c 2 Jul 2012 12:05:00 -0000 1.110 +++ main.c 18 Jul 2012 22:21:18 -0000 @@ -471,8 +471,6 @@ captured_main (void *data) {"args", no_argument, &set_args, 1}, {"l", required_argument, 0, 'l'}, {"return-child-result", no_argument, &return_child_result, 1}, - {"use-deprecated-index-sections", no_argument, - &use_deprecated_index_sections, 1}, {0, no_argument, 0, 0} }; Index: symfile.h =================================================================== RCS file: /cvs/src/src/gdb/symfile.h,v retrieving revision 1.110 diff -u -p -r1.110 symfile.h --- symfile.h 18 Jul 2012 16:12:17 -0000 1.110 +++ symfile.h 18 Jul 2012 22:21:18 -0000 @@ -673,9 +673,6 @@ extern void dwarf2_build_frame_info (str void dwarf2_free_objfile (struct objfile *); -/* Whether to use deprecated .gdb_index sections. */ -extern int use_deprecated_index_sections; - /* From mdebugread.c */ /* Hack to force structures to exist before use in parameter list. */ Index: doc/gdb.texinfo =================================================================== RCS file: /cvs/src/src/gdb/doc/gdb.texinfo,v retrieving revision 1.990 diff -u -p -r1.990 gdb.texinfo --- doc/gdb.texinfo 5 Jul 2012 01:08:24 -0000 1.990 +++ doc/gdb.texinfo 18 Jul 2012 22:21:19 -0000 @@ -1247,13 +1247,6 @@ memory usage after it completes each com This option causes @value{GDBN} to print its version number and no-warranty blurb, and exit. -@item -use-deprecated-index-sections -@cindex @code{--use-deprecated-index-sections} -This option causes @value{GDBN} to read and use deprecated -@samp{.gdb_index} sections from symbol files. This can speed up -startup, but may result in some functionality being lost. -@xref{Index Section Format}. - @end table @node Startup @@ -16753,6 +16746,15 @@ $ objcopy --add-section .gdb_index=symfi --set-section-flags .gdb_index=readonly symfile symfile @end smallexample +@value{GDBN} will normally ignore older versions of @file{.gdb_index} +sections that have been deprecated. Usually they are deprecated because +they are missing a new feature or have performance issues. +To tell @value{GDBN} to use a deprecated index section anyway +specify @code{set use-deprecated-index-sections on}. +The default is @code{off}. +This can speed up startup, but may result in some functionality being lost. +@xref{Index Section Format}. + There are currently some limitation on indices. They only work when for DWARF debugging information, not stabs. And, they do not currently work for programs using Ada. @@ -40408,7 +40410,7 @@ Version 4 uses a different hashing funct Version 6 includes symbols for inlined functions, whereas versions 4 and 5 do not. Version 7 adds attributes to the CU indices in the symbol table. @value{GDBN} will only read version 4, 5, or 6 indices -if the @code{--use-deprecated-index-sections} option is used. +by specifying @code{set use-deprecated-index-sections on}. @item The offset, from the start of the file, of the CU list.