From patchwork Thu Jul 13 10:24:10 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Guinevere Larsen X-Patchwork-Id: 72628 Return-Path: X-Original-To: patchwork@sourceware.org Delivered-To: patchwork@sourceware.org Received: from server2.sourceware.org (localhost [IPv6:::1]) by sourceware.org (Postfix) with ESMTP id 31379385E45D for ; Thu, 13 Jul 2023 10:25:17 +0000 (GMT) DKIM-Filter: OpenDKIM Filter v2.11.0 sourceware.org 31379385E45D DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sourceware.org; s=default; t=1689243917; bh=1A4AJHTKm3e+AjqHXUfSqSTXt6Y8lW6JJliDqPcWK2w=; h=To:Cc:Subject:Date:In-Reply-To:References:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: From:Reply-To:From; b=jC7oX8uQe2Eq0LbJCqgMWFThmb0ETkv4+Phy8QHXLF+RfuFoa0CtA5QBoDa0k/Z9u q3+EQYW0/QvbmYofyzrDTp2mFMktb4TYfS+H7JgLr58td1vl/34RH6P1utG0SCYDe2 VPTIneyBZmbbwtkybRpwsyWb3Kml4vbYrhpii9Aw= X-Original-To: gdb-patches@sourceware.org Delivered-To: gdb-patches@sourceware.org Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by sourceware.org (Postfix) with ESMTPS id 92856385AF82 for ; Thu, 13 Jul 2023 10:24:26 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.4.2 sourceware.org 92856385AF82 Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-620-HaDF6GAZNY-0bUvUn3ibqQ-1; Thu, 13 Jul 2023 06:24:24 -0400 X-MC-Unique: HaDF6GAZNY-0bUvUn3ibqQ-1 Received: from smtp.corp.redhat.com (int-mx01.intmail.prod.int.rdu2.redhat.com [10.11.54.1]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 86891800B35 for ; Thu, 13 Jul 2023 10:24:24 +0000 (UTC) Received: from fedora.redhat.com (unknown [10.45.226.146]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 0F08440C2063; Thu, 13 Jul 2023 10:24:23 +0000 (UTC) To: gdb-patches@sourceware.org Cc: Bruno Larsen Subject: [PATCH v4 3/4] gdb/cli: Improve UX when using list with no args Date: Thu, 13 Jul 2023 12:24:10 +0200 Message-ID: <20230713102411.2279542-4-blarsen@redhat.com> In-Reply-To: <20230713102411.2279542-1-blarsen@redhat.com> References: <20230713102411.2279542-1-blarsen@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 3.1 on 10.11.54.1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-Spam-Status: No, score=-15.6 required=5.0 tests=BAYES_00, DKIM_INVALID, DKIM_SIGNED, GIT_PATCH_0, KAM_DMARC_NONE, KAM_DMARC_STATUS, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H4, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_NONE, 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 X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-Patchwork-Original-From: Bruno Larsen via Gdb-patches From: Guinevere Larsen Reply-To: Bruno Larsen Errors-To: gdb-patches-bounces+patchwork=sourceware.org@sourceware.org Sender: "Gdb-patches" When using "list" with no arguments, GDB will first print the lines around where the inferior is stopped, then print the next N lines until reaching the end of file, at which point it wanrs the user "Line X out of range, file Y only has X-1 lines.". This is usually desireable, but if the user can no longer see the original line, they may have forgotten the current line or that a list command was used at all, making GDB's error message look cryptic. It was reported in bugzilla as PR cli/30497. This commit improves the user experince by changing the behavior of "list" slightly when a user passes no arguments. It now prints that the end of the file has been reached and recommends that the user use the command "list ." instead. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=30497 Reviewed-By: Eli Zaretskii --- gdb/NEWS | 5 +++++ gdb/cli/cli-cmds.c | 17 +++++++++++++---- gdb/doc/gdb.texinfo | 4 +++- gdb/source.c | 16 ++++++++++++++++ gdb/source.h | 7 +++++++ gdb/testsuite/gdb.base/list.exp | 8 ++++---- 6 files changed, 48 insertions(+), 9 deletions(-) diff --git a/gdb/NEWS b/gdb/NEWS index eef440a5242..df26606c9a8 100644 --- a/gdb/NEWS +++ b/gdb/NEWS @@ -88,6 +88,11 @@ print the location where the inferior is stopped. If the inferior hasn't started yet, the command will print around the main function. +* Using the 'list' command with no arguments in a situation where the + command would attempt to list past the end of the file now warns the + user that the end of file has been reached, refers the user to the + newly added '.' argument + * New commands maintenance print record-instruction [ N ] diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c index 1c459afdc97..5f5933e7963 100644 --- a/gdb/cli/cli-cmds.c +++ b/gdb/cli/cli-cmds.c @@ -1246,10 +1246,19 @@ list_command (const char *arg, int from_tty) list_around_line (arg, cursal); } - /* "l" or "l +" lists next ten lines. */ - else if (arg == NULL || arg[0] == '+') - print_source_lines (cursal.symtab, - source_lines_range (cursal.line), 0); + /* "l" and "l +" lists the next few lines, unless we're listing past + the end of the file. */ + else if (arg == nullptr || arg[0] == '+') + { + if (last_symtab_line (cursal.symtab) >= cursal.line) + print_source_lines (cursal.symtab, + source_lines_range (cursal.line), 0); + else + { + error (_("End of the file was already reached, use \"list .\" to" + " list the current location again")); + } + } /* "l -" lists previous ten lines, the ones before the ten just listed. */ diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 7619efe3de9..20c9b24400d 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -9144,7 +9144,9 @@ Print more lines. If the last lines printed were printed with a @code{list} command, this prints lines following the last lines printed; however, if the last line printed was a solitary line printed as part of displaying a stack frame (@pxref{Stack, ,Examining the -Stack}), this prints lines centered around that line. +Stack}), this prints lines centered around that line. If no +@code{list} command has been used and no solitary line was printed, +it prints the lines around the function @code{main}. @item list - Print lines just before the lines last printed. diff --git a/gdb/source.c b/gdb/source.c index 9997cccb31b..08adc6671b7 100644 --- a/gdb/source.c +++ b/gdb/source.c @@ -1484,6 +1484,22 @@ print_source_lines (struct symtab *s, source_lines_range line_range, line_range.stopline (), flags); } +/* See source.h. */ + +int +last_symtab_line (struct symtab *s) +{ + const std::vector *offsets; + + /* Try to get the offsets for the start of each line. */ + if (!g_source_cache.get_line_charpos (s, &offsets)) + return false; + if (offsets == nullptr) + return false; + + return offsets->size (); +} + /* Print info on range of pc's in a specified line. */ diff --git a/gdb/source.h b/gdb/source.h index 8fbc365680d..be80e003890 100644 --- a/gdb/source.h +++ b/gdb/source.h @@ -192,6 +192,13 @@ class source_lines_range int m_stopline; }; +/* Get the number of the last line in the given symtab. */ +extern int last_symtab_line (struct symtab *s); + +/* Check if the line LINE can be found in the symtab S, so that it can be + printed. */ +extern bool can_print_line (struct symtab *s, int line); + /* Variation of previous print_source_lines that takes a range instead of a start and end line number. */ extern void print_source_lines (struct symtab *s, source_lines_range r, diff --git a/gdb/testsuite/gdb.base/list.exp b/gdb/testsuite/gdb.base/list.exp index ed178a1dd95..582355996b0 100644 --- a/gdb/testsuite/gdb.base/list.exp +++ b/gdb/testsuite/gdb.base/list.exp @@ -175,8 +175,8 @@ proc_with_prefix test_list_forward {} { "list 25-34" gdb_test "list" "35\[ \t\]+foo \\(.*\\);.*${last_line_re}" \ "list 35-42" - gdb_test "list" "Line number 44 out of range; \[^\r\n\]+ has 43 lines\." \ - "end of file error after \"list\" command" + gdb_test "list" "End of the file was already reached, use \"list .\" to list the current location again" \ + "list past end of file" } # Test that repeating the list linenum command doesn't print the same @@ -194,8 +194,8 @@ proc_with_prefix test_repeat_list_command {} { "list 25-34" gdb_test " " "35\[ \t\]+foo \\(.*\\);.*${last_line_re}" \ "list 35-42" - gdb_test "list" "Line number 44 out of range; \[^\r\n\]+ has 43 lines\." \ - "end of file error after using 'return' to repeat the list command" + gdb_test "list" "End of the file was already reached, use \"list .\" to list the current location again" \ + "list past end of file" } proc_with_prefix test_list_backwards {} {