From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr1-f51.google.com (mail-wr1-f51.google.com [209.85.221.51]) by sourceware.org (Postfix) with ESMTPS id 7B1243858CD1 for ; Fri, 14 Jul 2023 17:50:36 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 7B1243858CD1 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-f51.google.com with SMTP id ffacd0b85a97d-31434226a2eso2388170f8f.1 for ; Fri, 14 Jul 2023 10:50:36 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1689357035; x=1691949035; h=content-transfer-encoding:in-reply-to:from:references:to :content-language:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=J0BWj04dRLpwdqAY9u1/1kKsI4qpCtsO6M7Co1HIbOc=; b=E2XfxLiEiJ1+1Xhy38suq5GHywr/Yrk7O/DFsPTELqJ8C8qs4mxfBYnafWEQVn2hma /P4bIXivCRcGfstL+5qpRwLkWXULz6qZxzLmoD6OmRiCbnOICW1Hmm1AR43WQ8LMT0nK 0ULUY1i8APsRet17soqwiWdOhWZBXnqKybmR+8U/JdVkpRvq/cBIo/L5ECNcrgvH0A8H 7iluiZGony0UhjEXyrhGRorAwrKiaBwaHkXC3WOkvvbjrXFyK3JCgi/yR2IniCh1XLb2 n9QToRBH+AxI3uGrMa0YfY5kuCiYVkEa3X41n+h1QRJM4TCAd9wUBEhSIRo2NjkZBjWk bLtw== X-Gm-Message-State: ABy/qLa7cN+vSuxbjlLuFP+8ptRt4zgFHjBX47/GgEc82cwvrUgrI0i5 zN3SoLpBo4vKGyl0DZEcEJQbIKJcsgw= X-Google-Smtp-Source: APBJJlF0rp6fbtRs5STfa2SwFP8sslXvCoxcGdJqR3plqZHgG3hzmUFcytA93idv7Q7NzALQA7EaYQ== X-Received: by 2002:adf:f106:0:b0:316:efb9:101d with SMTP id r6-20020adff106000000b00316efb9101dmr2303596wro.25.1689357034772; Fri, 14 Jul 2023 10:50:34 -0700 (PDT) Received: from ?IPV6:2001:8a0:f91d:bc00:98b3:dfb7:8070:8955? ([2001:8a0:f91d:bc00:98b3:dfb7:8070:8955]) by smtp.gmail.com with ESMTPSA id n8-20020a5d6b88000000b003141e9e2f81sm11544884wrx.4.2023.07.14.10.50.34 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 14 Jul 2023 10:50:34 -0700 (PDT) Message-ID: <835af40f-edae-ba48-f121-a1cdd1f1147e@palves.net> Date: Fri, 14 Jul 2023 18:50:33 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.13.0 Subject: Re: [PATCH v4 2/4] gdb/cli: add '.' as an argument for 'list' command Content-Language: en-US To: Bruno Larsen , gdb-patches@sourceware.org References: <20230713102411.2279542-1-blarsen@redhat.com> <20230713102411.2279542-3-blarsen@redhat.com> From: Pedro Alves In-Reply-To: <20230713102411.2279542-3-blarsen@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Spam-Status: No, score=-9.9 required=5.0 tests=BAYES_00,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM,GIT_PATCH_0,HEADER_FROM_DIFFERENT_DOMAINS,KAM_DMARC_STATUS,NICE_REPLY_A,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_NONE,SPF_PASS,TXREP,T_SCC_BODY_TEXT_LINE 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: Hi, Sorry for coming late to the party here, but while trying to catch up on the list I spotted a few things that I think should be fixed. See below. BTW, I think the feature is cool! On 2023-07-13 11:24, Bruno Larsen via Gdb-patches wrote: > Currently, after the user has used the list command once, there is no > self-contained way to ask GDB to print the location where the inferior is > stopped. The current best options require either using a separate > command to scope out where the inferior is stopped, or using "list *$pc" > requiring knowledge of GDB standard registers. This commit adds a way > to do that using '.' as a new argument for the 'list' command. If the > inferior isn't running, the command prints around the main function. > > Because this necessitated having the inferior running and the test was > (seemingly unnecessarily) using printf in a non-essential way and it > would make the resulting log harder to read for no benefit, it was > replaced by a differen t statement. > --- > gdb/NEWS | 4 ++++ > gdb/cli/cli-cmds.c | 31 ++++++++++++++++++++++++-- > gdb/doc/gdb.texinfo | 5 +++++ > gdb/testsuite/gdb.base/list.exp | 39 +++++++++++++++++++++++++++++++++ > gdb/testsuite/gdb.base/list1.c | 2 +- > 5 files changed, 78 insertions(+), 3 deletions(-) > > diff --git a/gdb/NEWS b/gdb/NEWS > index b924834d3d7..eef440a5242 100644 > --- a/gdb/NEWS > +++ b/gdb/NEWS > @@ -84,6 +84,10 @@ > is 64k. To print longer strings you should increase > 'max-value-size'. > > +* The 'list' command now accepts '.' as an argument, which tells GDB to > + print the location where the inferior is stopped. If the inferior hasn't > + started yet, the command will print around the main function. It would be more accurate to say that it's where the current thread is stopped. Say you run to breakpoint hit in thread 1, and then switch to thread 2, and then do "list .". That will show you the current frame of thread 2, while "where the inferior is stopped" could very well be interpreted as "thread 1". > + > * New commands > > maintenance print record-instruction [ N ] > diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c > index 00977bc2ee3..1c459afdc97 100644 > --- a/gdb/cli/cli-cmds.c > +++ b/gdb/cli/cli-cmds.c > @@ -1234,14 +1234,14 @@ list_command (const char *arg, int from_tty) > const char *p; > > /* Pull in the current default source line if necessary. */ > - if (arg == NULL || ((arg[0] == '+' || arg[0] == '-') && arg[1] == '\0')) > + if (arg == NULL || ((arg[0] == '+' || arg[0] == '-' || arg[0] == '.') && arg[1] == '\0')) > { > set_default_source_symtab_and_line (); > symtab_and_line cursal = get_current_source_symtab_and_line (); > > /* If this is the first "list" since we've set the current > source line, center the listing around that line. */ > - if (get_first_line_listed () == 0) > + if (get_first_line_listed () == 0 && (arg == nullptr || arg[0] != '.')) > { > list_around_line (arg, cursal); > } > @@ -1263,6 +1263,32 @@ list_command (const char *arg, int from_tty) > print_source_lines (cursal.symtab, range, 0); > } > > + /* "l ." lists the default location again. */ Spelling out "list ." would be better for grepping, IMHO. > + else if (arg[0] == '.') > + { > + try > + { > + /* Find the current line by getting the PC of the currently > + selected frame, and finding the line associated to it. */ > + frame_info_ptr frame = get_selected_frame (nullptr); So this is actually using the selected frame, not the current frame. So even the "where the thread is stopped" description would be incorrect. If you really wanted to use frame #0 (where the thread stopped), then this should use get_current_frame. > + CORE_ADDR curr_pc = get_frame_pc (frame); > + cursal = find_pc_line (curr_pc, 0); > + } > + catch (const gdb_exception &e) > + { > + /* If there was an exception above, it means the inferior > + is not running, so reset the current source location to > + the default. */ Aww. Please don't use a try/catch for this... You can just check target_has_execution. Also, if an exception would be good for this (which it isn't), please don't catch gdb_exception -- it catches QUIT/Ctrl-C as well, which is most often wrong. You would want gdb_exception_error normally. > + clear_current_source_symtab_and_line (); > + set_default_source_symtab_and_line (); > + cursal = get_current_source_symtab_and_line (); > + } > + list_around_line (arg, cursal); > + /* Advance argument so just pressing "enter" after using "list ." > + will print the following lines instead of the same lines again. */ > + arg++; > + } > + > return; > } > > @@ -2770,6 +2796,7 @@ and send its output to SHELL_COMMAND.")); > = add_com ("list", class_files, list_command, _("\ > List specified function or line.\n\ > With no argument, lists ten more lines after or around previous listing.\n\ > +\"list .\" lists ten lines arond where the inferior is stopped.\n\ arond -> around > \"list -\" lists the ten lines before a previous ten-line listing.\n\ > One argument specifies a line, and ten lines are listed around that line.\n\ > Two arguments with comma between specify starting and ending lines to list.\n\ > diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo > index b10c06ae91f..7619efe3de9 100644 > --- a/gdb/doc/gdb.texinfo > +++ b/gdb/doc/gdb.texinfo > @@ -9148,6 +9148,11 @@ Stack}), this prints lines centered around that line. > > @item list - > Print lines just before the lines last printed. > + > +@item list . > +Print the lines surrounding the location that is where the inferior > +is stopped. If the inferior is not running, print around the main > +function instead. This should be clarified as well. > @end table > > @cindex @code{list}, how many lines to display > diff --git a/gdb/testsuite/gdb.base/list.exp b/gdb/testsuite/gdb.base/list.exp > index 18ecd13ac0f..ed178a1dd95 100644 > --- a/gdb/testsuite/gdb.base/list.exp > +++ b/gdb/testsuite/gdb.base/list.exp > @@ -400,6 +400,42 @@ proc test_list_invalid_args {} { > "second use of \"list +INVALID\"" > } > > +proc test_list_current_location {} { > + global binfile > + # If the first "list" command that GDB runs is "list ." GDB may be > + # unable to recognize that the inferior isn't running, so we should > + # reload the inferior to test that condition. I don't understand this comment. Why would it be unable to do so? > + clean_restart > + gdb_file_cmd ${binfile} > + > + # Ensure that we are printing 10 lines > + if {![set_listsize 10]} { > + return > + } > + > + # First guarantee that GDB prints around the main function correctly > + gdb_test "list ." \ > + "1.*\r\n2\[ \t\]+\r\n3\[ \t\]+int main \[)(\]+.*5\[ \t\]+int x;.*" \ > + "list . with inferior not running" > + > + if {![runto_main]} { > + warning "couldn't start inferior" > + return > + } > + > + # Walk forward some lines Missing period. > + gdb_test "until 15" ".*15.*foo.*" > + > + # Test that the correct location is printed and that > + # using just "list" will print the following lines. > + gdb_test "list ." ".*" "list current line after starting" > + gdb_test "list" ".*" "confirm we are printing the following lines" > + > + # Test that list . will reset to current location > + gdb_test "list ." ".*" "list around current line again" > + gdb_test " " ".*" "testing repeated invocations with GDB's auto-repeat" I don't understand -- these 4 tests match ".*", so how how they ensuring what they claim they test? Looks like WIP? Pedro Alves > +} > + > clean_restart > gdb_file_cmd ${binfile} > > @@ -519,4 +555,7 @@ test_list "list -" 10 2 "7-8" "5-6" > # the current line. > test_list "list -" 10 1 "7" "6" > > +# Test printing the location where the inferior is stopped. > +test_list_current_location > + > remote_exec build "rm -f list0.h" > diff --git a/gdb/testsuite/gdb.base/list1.c b/gdb/testsuite/gdb.base/list1.c > index d694495c3fb..9297f958f46 100644 > --- a/gdb/testsuite/gdb.base/list1.c > +++ b/gdb/testsuite/gdb.base/list1.c > @@ -7,7 +7,7 @@ void bar (int x) > - > - */ > { > - printf ("%d\n", x); > + x++; > > long_line (); > }