From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f43.google.com (mail-wr1-f43.google.com [209.85.221.43]) by sourceware.org (Postfix) with ESMTPS id 083993889E38 for ; Thu, 2 Feb 2023 18:13:52 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 083993889E38 Authentication-Results: sourceware.org; dmarc=none (p=none dis=none) header.from=palves.net Authentication-Results: sourceware.org; spf=pass smtp.mailfrom=gmail.com Received: by mail-wr1-f43.google.com with SMTP id bk16so2476880wrb.11 for ; Thu, 02 Feb 2023 10:13:51 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:content-language:in-reply-to:mime-version :user-agent:date:message-id:from:references:to:subject :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=SqE8hTOAn2cxIBCVj9jQ8e1ORfHB1Sq+wt50L4ycZ4c=; b=C1EMugaVvXsSbFaBm8CDjxeYiPnUBAH/loF86tCmCt2uwMJBFCNxc16YnxRz0WVs6U iAo905WsyM2ykFTgR+0LEJBq8Qlj96ocIrHiR0DhYKPR6wUN+Jeji0qZ3m8SafcN4PpT zbmqFDAnTlQ8RVJFPpeq50PiYSazU86MfIfZTUs1VImNFiNlMbfKxqt4UqqiHbefruw2 XBp1V9KCJAcOqO2A/3pSjGvjlafq1Ggzh3BxuSVW7LSjcvlOd2keZtA1Q0Cnx7Kq3aPP WOUJe68J42qNvj5OxcsNKfifAD/hc9X6uXSlRXnE8ZbNjlXyoE6xTFzwOp5VJg7saA7r cf9w== X-Gm-Message-State: AO0yUKVEJvHNEKcMeAkmtVI+NX7JPHz8M5BL6mvTlqyHiTPgycyeW/Gf IITzHf6N4ugPgKa9OCd9ibfWcBSDrcXmTw== X-Google-Smtp-Source: AK7set8znABN3PJEql3IqegN+w8eK0x1ziHimTaxfTVNKczPB9zDCZAAhjv4cz4WyDcFHQoV//nHDQ== X-Received: by 2002:a05:6000:1105:b0:2bf:b5ec:4844 with SMTP id z5-20020a056000110500b002bfb5ec4844mr6260217wrw.19.1675361630622; Thu, 02 Feb 2023 10:13:50 -0800 (PST) Received: from ?IPv6:2001:8a0:f92b:9e00::1fe? ([2001:8a0:f92b:9e00::1fe]) by smtp.gmail.com with ESMTPSA id y16-20020a056000109000b002423edd7e50sm129805wrw.32.2023.02.02.10.13.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Feb 2023 10:13:50 -0800 (PST) Subject: Re: [PATCHv2 3/6] gdb: fix display of thread condition for multi-location breakpoints To: Andrew Burgess , gdb-patches@sourceware.org References: <403eeb015d985423d995b34a345e4e7816b8c349.1674207665.git.aburgess@redhat.com> From: Pedro Alves Message-ID: Date: Thu, 2 Feb 2023 18:13:49 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.10.1 MIME-Version: 1.0 In-Reply-To: <403eeb015d985423d995b34a345e4e7816b8c349.1674207665.git.aburgess@redhat.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-10.2 required=5.0 tests=BAYES_00,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,GIT_PATCH_0,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,KAM_SHORT,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on server2.sourceware.org List-Id: On 2023-01-20 9:46 a.m., Andrew Burgess via Gdb-patches wrote: > If a breakpoint with multiple locations has a thread condition, then > the 'info breakpoints' output is a little messed up, here's an example > of the current output: > > (gdb) break foo thread 1 > Breakpoint 2 at 0x401114: foo. (3 locations) > (gdb) break bar thread 1 > Breakpoint 3 at 0x40110a: file /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c, line 32. > (gdb) info breakpoints > Num Type Disp Enb Address What > 2 breakpoint keep y thread 1 > stop only in thread 1 > 2.1 y 0x0000000000401114 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 2.2 y 0x0000000000401146 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 2.3 y 0x0000000000401168 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 3 breakpoint keep y 0x000000000040110a in bar at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:32 thread 1 > stop only in thread 1 > > Notice that, at the end of the location for breakpoint 3, the 'thread > 1' condition is printed, but this is then repeated on the next line > with 'stop only in thread 1'. > > In contrast, for breakpoint 2, the 'thread 1' appears randomly, in the > "What" column, though slightly offset, non of the separate locations > have the 'thread 1' information. Additionally for breakpoint 2 we > also get a 'stop only in thread 1' line. > > There's two things going on here. First the randomly placed 'thread > 1' for breakpoint 2 is due to a bug in print_one_breakpoint_location, > where we check the variable part_of_multiple instead of > header_of_multiple. > > If I fix this oversight, then the output is now: > > (gdb) break foo thread 1 > Breakpoint 2 at 0x401114: foo. (3 locations) > (gdb) break bar thread 1 > Breakpoint 3 at 0x40110a: file /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c, line 32. > (gdb) info breakpoints > Num Type Disp Enb Address What > 2 breakpoint keep y > stop only in thread 1 > 2.1 y 0x0000000000401114 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 thread 1 > 2.2 y 0x0000000000401146 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 thread 1 > 2.3 y 0x0000000000401168 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 thread 1 > 3 breakpoint keep y 0x000000000040110a in bar at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:32 thread 1 > stop only in thread 1 > > The 'thread 1' condition is now displayed at the end of each location, > which makes the output the same for single location breakpoints and > multi-location breakpoints. > > However, there's still some duplication here. Both breakpoints 2 and > 3 include a 'stop only in thread 1' line, and it feels like the > additional 'thread 1' is redundant. In fact, there's a comment to > this very effect in the code: > > /* FIXME: This seems to be redundant and lost here; see the > "stop only in" line a little further down. */ > > So, lets fix this FIXME. The new plan is to remove all the trailing > 'thread 1' markers from the CLI output, we now get this: > > (gdb) break foo thread 1 > Breakpoint 2 at 0x401114: foo. (3 locations) > (gdb) break bar thread 1 > Breakpoint 3 at 0x40110a: file /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c, line 32. > (gdb) info breakpoints > Num Type Disp Enb Address What > 2 breakpoint keep y > stop only in thread 1 > 2.1 y 0x0000000000401114 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 2.2 y 0x0000000000401146 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 2.3 y 0x0000000000401168 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 > 3 breakpoint keep y 0x000000000040110a in bar at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:32 > stop only in thread 1 > This is the right direction, IMO. The "thread 1" string is at best part of the breakpoint's location spec, not of the code locations that spec resolved to. If we went forward with my proposal to always show breakpoints using the multi-locations mode, and, to include the location spec in the "What" column of the breakpoint header, we could show: (gdb) info breakpoints Num Type Disp Enb Address What 2 breakpoint keep y foo thread 1 stop only in thread 1 2.1 y 0x0000000000401114 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 2.2 y 0x0000000000401146 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 2.3 y 0x0000000000401168 in foo at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:25 3 breakpoint keep y bar thread 1 stop only in thread 1 3.1 breakpoint keep y 0x000000000040110a in bar at /tmp/src/gdb/testsuite/gdb.base/thread-bp-multi-loc.c:32 ... for instance. Or not include the "thread 1". But my point is that if we were to show it, that's where we would show it, not in the breapoint locations. > All of the above points are also true for the Ada 'task' breakpoint > condition, and the changes I've made also update how the task > information is printed, though in the case of the Ada task there was > no 'stop only in task XXX' line printed, so I've added one of those. > > Obviously it can't be quite that easy. For MI backwards compatibility > I've retained the existing code (but now only for MI like outputs), > which ensures we should generate backwards compatible output. > > I've extended an Ada test to cover the new task related output, and > updated all the tests I could find that checked for the old output. > --- > gdb/breakpoint.c | 30 ++++---- > gdb/testsuite/gdb.ada/tasks.exp | 15 ++-- > gdb/testsuite/gdb.base/save-bp.exp | 2 +- > gdb/testsuite/gdb.base/thread-bp-multi-loc.c | 44 ++++++++++++ > .../gdb.base/thread-bp-multi-loc.exp | 72 +++++++++++++++++++ > 5 files changed, 141 insertions(+), 22 deletions(-) > create mode 100644 gdb/testsuite/gdb.base/thread-bp-multi-loc.c > create mode 100644 gdb/testsuite/gdb.base/thread-bp-multi-loc.exp > > diff --git a/gdb/breakpoint.c b/gdb/breakpoint.c > index 00cc2ab401c..b2cd89511fb 100644 > --- a/gdb/breakpoint.c > +++ b/gdb/breakpoint.c > @@ -6468,20 +6468,19 @@ print_one_breakpoint_location (struct breakpoint *b, > output_thread_groups (uiout, "thread-groups", inf_nums, mi_only); > } > > - if (!part_of_multiple) > + /* In the MI output, each location of a thread or task specific > + breakpoint is with the relevant thread or task ID. This is done for > + backwards compatibility reasons. Is "is with" idiomatic English meaning "includes"? I don't think I ever heard that. Or is some word missing somewhere? I'd suggest using "includes" or some such instead. > + > + For the CLI output, the thread/task information is printed on a > + separate line, see the 'stop only in thread' and 'stop only in task' > + output below. */ > + if (!header_of_multiple && uiout->is_mi_like_p ()) > { > if (b->thread != -1) > - { > - /* FIXME: This seems to be redundant and lost here; see the > - "stop only in" line a little further down. */ > - uiout->text (" thread "); > - uiout->field_signed ("thread", b->thread); > - } > + uiout->field_signed ("thread", b->thread); > else if (b->task != 0) > - { > - uiout->text (" task "); > - uiout->field_signed ("task", b->task); > - } > + uiout->field_signed ("task", b->task); > } > > uiout->text ("\n"); > @@ -6536,7 +6535,14 @@ print_one_breakpoint_location (struct breakpoint *b, > } > uiout->text ("\n"); > } > - > + > + if (!part_of_multiple && b->task != 0) > + { > + uiout->text ("\tstop only in task "); > + uiout->field_signed ("task", b->task); > + uiout->text ("\n"); > + } > + > if (!part_of_multiple) > { > if (b->hit_count) > diff --git a/gdb/testsuite/gdb.ada/tasks.exp b/gdb/testsuite/gdb.ada/tasks.exp > index a9b58f20cf6..23bf3937a20 100644 > --- a/gdb/testsuite/gdb.ada/tasks.exp > +++ b/gdb/testsuite/gdb.ada/tasks.exp > @@ -46,21 +46,18 @@ gdb_test "info tasks" \ > # breakpoint in the list that matched the triggered-breakpoint's > # address, no matter which task it was specific to. > gdb_test "break break_me task 1" "Breakpoint .* at .*" > +gdb_test "info breakpoints" "foo.adb:${decimal}\r\n\\s+stop only in task 1" \ > + "check info breakpoints for task 1 breakpoint" > > # Now, insert a breakpoint that should stop only if task 3 stops, and > # extract its number. > -set bp_number -1 > -set test "break break_me task 3" > -gdb_test_multiple $test $test { > - -re "Breakpoint (.*) at .*$gdb_prompt $" { > - set bp_number $expect_out(1,string) > - pass $test > - } > -} > - > +gdb_breakpoint "break_me task 3" > +set bp_number [get_integer_valueof "\$bpnum" -1] > if {$bp_number < 0} { > return > } > +gdb_test "info breakpoints" "foo.adb:${decimal}\r\n\\s+stop only in task 3" \ > + "check info breakpoints for task 3 breakpoint" > > # Continue to that breakpoint. Task 2 should hit it first, and GDB > # is expected to ignore that hit and resume the execution. Only then > diff --git a/gdb/testsuite/gdb.base/save-bp.exp b/gdb/testsuite/gdb.base/save-bp.exp > index a39712c7f5c..41d71837fb6 100644 > --- a/gdb/testsuite/gdb.base/save-bp.exp > +++ b/gdb/testsuite/gdb.base/save-bp.exp > @@ -79,7 +79,7 @@ gdb_test_sequence "info break" "info break" [list \ > "\[\r\n\]+Num +Type +Disp +Enb +Address +What" \ > "\[\r\n\]+$bp_row_start break_me at \[^\r\n\]*$srcfile:\[0-9\]+" \ > "\[\r\n\]+$bp_row_start main at \[^\r\n\]*$srcfile:$loc_bp2" \ > - "\[\r\n\]+$bp_row_start main at \[^\r\n\]*$srcfile:$loc_bp3 +thread 1" \ > + "\[\r\n\]+$bp_row_start main at \[^\r\n\]*$srcfile:$loc_bp3" \ > "\[\r\n\]+\[ \t]+stop only in thread 1" \ > "\[\r\n\]+$bp_row_start main at \[^\r\n\]*$srcfile:$loc_bp4" \ > "\[\r\n\]+\[ \t\]+stop only if i == 1( \\((host|target) evals\\))?" \ > diff --git a/gdb/testsuite/gdb.base/thread-bp-multi-loc.c b/gdb/testsuite/gdb.base/thread-bp-multi-loc.c > new file mode 100644 > index 00000000000..cab009c39ec > --- /dev/null > +++ b/gdb/testsuite/gdb.base/thread-bp-multi-loc.c > @@ -0,0 +1,44 @@ > +/* This testcase is part of GDB, the GNU debugger. > + > + Copyright 2022 Free Software Foundation, Inc. Needs to include 2023 in range now. > + > + This program is free software; you can redistribute it and/or modify > + it under the terms of the GNU General Public License as published by > + the Free Software Foundation; either version 3 of the License, or > + (at your option) any later version. > + > + This program is distributed in the hope that it will be useful, > + but WITHOUT ANY WARRANTY; without even the implied warranty of > + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + GNU General Public License for more details. > + > + You should have received a copy of the GNU General Public License > + along with this program. If not, see . */ > + > +volatile int global_var = 0; > + > +__attribute__((__always_inline__)) static inline void > +foo (void) > +{ > + int i; > + > + for (i = 0; i < 10; ++i) > + global_var = i; > +} > + > +static void > +bar (void) > +{ > + global_var = 0; > + foo (); > +} > + > +int > +main (void) > +{ > + global_var = 0; > + foo (); > + bar (); > + foo (); > + return 0; > +} > diff --git a/gdb/testsuite/gdb.base/thread-bp-multi-loc.exp b/gdb/testsuite/gdb.base/thread-bp-multi-loc.exp > new file mode 100644 > index 00000000000..9665fe9e21f > --- /dev/null > +++ b/gdb/testsuite/gdb.base/thread-bp-multi-loc.exp > @@ -0,0 +1,72 @@ > +# Copyright 2022 Free Software Foundation, Inc. Ditto. > + > +# This program is free software; you can redistribute it and/or modify > +# it under the terms of the GNU General Public License as published by > +# the Free Software Foundation; either version 3 of the License, or > +# (at your option) any later version. > +# > +# This program is distributed in the hope that it will be useful, > +# but WITHOUT ANY WARRANTY; without even the implied warranty of > +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > +# GNU General Public License for more details. > +# > +# You should have received a copy of the GNU General Public License > +# along with this program. If not, see . > + > +# Create a multi-location breakpoint with a thread condition, then check the > +# output of 'info breakpoints' to ensure that the thread condition is > +# displayed correctly. > + > +standard_testfile > + > +if { [prepare_for_testing "failed to prepare" $testfile $srcfile] } { > + return -1 > +} > + > +if {![runto_main]} { > + return -1 > +} > + > +delete_breakpoints > + > +gdb_breakpoint "foo thread 1" > +set bp_number [get_integer_valueof "\$bpnum" 0] > +if { $bp_number == 0 } { > + unresolved "breakpoint not placed correctly" > + return -1 > +} > + > +set saw_header false > +set saw_cond false > +set loc_count 0 > +gdb_test_multiple "info breakpoints" "" { > + -re "\r\nNum\\s+\[^\r\n\]+\r\n" { > + exp_continue > + } > + > + -re "^$bp_number\\s+breakpoint\\s+keep\\s+y\\s+\\s*\r\n" { > + set saw_header true > + exp_continue > + } > + > + -re "^\\s+stop only in thread 1\r\n" { > + set saw_cond true > + exp_continue > + } > + > + -re "^$bp_number\\.\[123\]\\s+\[^\r\n\]+:${decimal}\r\n" { > + incr loc_count > + exp_continue > + } > + > + -re "^$gdb_prompt $" { > + with_test_prefix $gdb_test_name { > + gdb_assert { $saw_header } \ > + "saw header line" > + gdb_assert { $saw_cond } \ > + "saw b/p condition line" > + gdb_assert { $loc_count == 3 } \ > + "saw all three locations" It's better if the tests are written such that FAIL/PASSes match. In this case, if gdb_test_multiple hits an internal pattern, then we'll have a single FAIL: info breakpoints To fix that, we should merge those three gdb_asserts into a single gdb_assert, and we should $gdb_test_name for its test name, along with passing a meaningful test name to gdb_test_multiple, so internal FAILs get that meaningful name as well. If we want to show the individual conditions, that can still be done by outputting them to the log. Pedro Alves > + } > + } > +} >