From patchwork Tue Apr 25 19:41:04 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Tromey X-Patchwork-Id: 20142 Received: (qmail 22033 invoked by alias); 25 Apr 2017 19:41:34 -0000 Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Unsubscribe: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org Delivered-To: mailing list gdb-patches@sourceware.org Received: (qmail 21928 invoked by uid 89); 25 Apr 2017 19:41:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-23.9 required=5.0 tests=AWL, BAYES_00, GIT_PATCH_0, GIT_PATCH_1, GIT_PATCH_2, GIT_PATCH_3, RCVD_IN_DNSWL_NONE, RCVD_IN_SORBS_SPAM, SPF_PASS autolearn=ham version=3.3.2 spammy=filters, H*Ad:U*tom X-HELO: gproxy3.mail.unifiedlayer.com Received: from gproxy3-pub.mail.unifiedlayer.com (HELO gproxy3.mail.unifiedlayer.com) (69.89.30.42) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Tue, 25 Apr 2017 19:41:31 +0000 Received: from cmgw3 (unknown [10.0.90.84]) by gproxy3.mail.unifiedlayer.com (Postfix) with ESMTP id 1C4EB40375 for ; Tue, 25 Apr 2017 13:41:32 -0600 (MDT) Received: from box522.bluehost.com ([74.220.219.122]) by cmgw3 with id CjhV1v0032f2jeq01jhYoY; Tue, 25 Apr 2017 13:41:32 -0600 X-Authority-Analysis: v=2.2 cv=VKStp5HX c=1 sm=1 tr=0 a=GsOEXm/OWkKvwdLVJsfwcA==:117 a=GsOEXm/OWkKvwdLVJsfwcA==:17 a=AzvcPWV-tVgA:10 a=zstS-IiYAAAA:8 a=KKAkSRfTAAAA:8 a=0FD05c-RAAAA:8 a=edjJ-nqE6KNgpsE6FPkA:9 a=4G6NA9xxw8l3yy4pmD5M:22 a=cvBusfyB2V15izCimMoJ:22 a=l1rpMCqCXRGZwUSuRcM3:22 Received: from 75-166-63-71.hlrn.qwest.net ([75.166.63.71]:40598 helo=bapiya.Home) by box522.bluehost.com with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.87) (envelope-from ) id 1d36L2-0000OG-Ql; Tue, 25 Apr 2017 13:41:28 -0600 From: Tom Tromey To: gdb-patches@sourceware.org Cc: Tom Tromey Subject: [RFA 01/10] Rationalize "backtrace" command line parsing Date: Tue, 25 Apr 2017 13:41:04 -0600 Message-Id: <20170425194113.17862-2-tom@tromey.com> In-Reply-To: <20170425194113.17862-1-tom@tromey.com> References: <20170425194113.17862-1-tom@tromey.com> X-BWhitelist: no X-Exim-ID: 1d36L2-0000OG-Ql X-Source-Sender: 75-166-63-71.hlrn.qwest.net (bapiya.Home) [75.166.63.71]:40598 X-Source-Auth: tom+tromey.com X-Email-Count: 2 X-Source-Cap: ZWx5bnJvYmk7ZWx5bnJvYmk7Ym94NTIyLmJsdWVob3N0LmNvbQ== The backtrace command has peculiar command-line parsing. In particular, it splits the command line, then loops over the arguments. If it sees a word it recognizes, like "full", it effectively drops this word from the argument vector. Then, it pastes together the remaining arguments, passing them on to backtrace_command_1, which in turn passes the resulting string to parse_and_eval_long. The documentation doesn't mention the parse_and_eval_long at all, so it is a bit of a hidden feature that you can "bt 3*2". The strange algorithm above also means you can "bt 3 * no-filters 2" and get 6 frames... This patch changes backtrace's command line parsing to be a bit more rational. Now, special words like "full" are only recognized at the start of the command. This also updates the documentation to describe the various bt options individually. ChangeLog 2017-04-25 Tom Tromey * stack.c (backtrace_command): Rewrite command line parsing. doc/ChangeLog 2017-04-25 Tom Tromey * gdb.texinfo (Backtrace): Describe options individually. --- gdb/ChangeLog | 4 +++ gdb/doc/ChangeLog | 4 +++ gdb/doc/gdb.texinfo | 50 ++++++++++++++----------------------- gdb/stack.c | 71 ++++++++++++++++++++--------------------------------- 4 files changed, 53 insertions(+), 76 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index 90ce6ae..48f2063 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,7 @@ +2017-04-25 Tom Tromey + + * stack.c (backtrace_command): Rewrite command line parsing. + 2017-04-25 Yao Qi * aarch64-tdep.c (aarch64_gdbarch_init): Don't call diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog index 9be035c..cf2226c 100644 --- a/gdb/doc/ChangeLog +++ b/gdb/doc/ChangeLog @@ -1,3 +1,7 @@ +2017-04-25 Tom Tromey + + * gdb.texinfo (Backtrace): Describe options individually. + 2017-04-21 Simon Marchi * gdb.texinfo (GDB/MI Thread Information): Add missing diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index f2e6156..a9f12fd 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -7199,39 +7199,27 @@ frame (frame zero), followed by its caller (frame one), and on up the stack. @anchor{backtrace-command} -@table @code @kindex backtrace @kindex bt @r{(@code{backtrace})} -@item backtrace -@itemx bt -Print a backtrace of the entire stack: one line per frame for all -frames in the stack. - -You can stop the backtrace at any time by typing the system interrupt -character, normally @kbd{Ctrl-c}. - -@item backtrace @var{n} -@itemx bt @var{n} -Similar, but print only the innermost @var{n} frames. - -@item backtrace -@var{n} -@itemx bt -@var{n} -Similar, but print only the outermost @var{n} frames. - -@item backtrace full -@itemx bt full -@itemx bt full @var{n} -@itemx bt full -@var{n} -Print the values of the local variables also. As described above, -@var{n} specifies the number of frames to print. - -@item backtrace no-filters -@itemx bt no-filters -@itemx bt no-filters @var{n} -@itemx bt no-filters -@var{n} -@itemx bt no-filters full -@itemx bt no-filters full @var{n} -@itemx bt no-filters full -@var{n} +Print a backtrace of the entire stack, use the @code{backtrace} +command, or its alias @code{bt}. This command will print one line per +frame for all frames in the stack. You can stop the backtrace at any +time by typing the system interrupt character, normally @kbd{Ctrl-c}. +@code{backtrace} can accept some arguments: + +@table @code +@item @var{n} +@itemx @var{n} +Print only the innermost @var{n} frames. + +@item -@var{n} +@itemx -@var{n} +Print only the outermost @var{n} frames. + +@item full +Print the values of the local variables also. + +@item no-filters Do not run Python frame filters on this backtrace. @xref{Frame Filter API}, for more information. Additionally use @ref{disable frame-filter all} to turn off all frame filters. This is only diff --git a/gdb/stack.c b/gdb/stack.c index 7f8a51c..c2fc3f1 100644 --- a/gdb/stack.c +++ b/gdb/stack.c @@ -1868,65 +1868,46 @@ backtrace_command_1 (char *count_exp, int show_locals, int no_filters, static void backtrace_command (char *arg, int from_tty) { - struct cleanup *old_chain = make_cleanup (null_cleanup, NULL); - int fulltrace_arg = -1, arglen = 0, argc = 0, no_filters = -1; - int user_arg = 0; + bool fulltrace = false; + bool filters = true; if (arg) { - char **argv; - int i; + bool done = false; - argv = gdb_buildargv (arg); - make_cleanup_freeargv (argv); - argc = 0; - for (i = 0; argv[i]; i++) + while (!done) { unsigned int j; + char *this_arg = extract_arg (&arg); - for (j = 0; j < strlen (argv[i]); j++) - argv[i][j] = TOLOWER (argv[i][j]); + if (this_arg == NULL) + break; + + struct cleanup *arg_cleanup = make_cleanup (xfree, this_arg); + + for (j = 0; j < strlen (this_arg); j++) + this_arg[j] = TOLOWER (this_arg[j]); - if (no_filters < 0 && subset_compare (argv[i], "no-filters")) - no_filters = argc; + if (subset_compare (this_arg, "no-filters")) + filters = false; + else if (subset_compare (this_arg, "full")) + fulltrace = true; else { - if (fulltrace_arg < 0 && subset_compare (argv[i], "full")) - fulltrace_arg = argc; - else - { - user_arg++; - arglen += strlen (argv[i]); - } + /* Not a recognized argument, so stop. */ + done = true; } - argc++; - } - arglen += user_arg; - if (fulltrace_arg >= 0 || no_filters >= 0) - { - if (arglen > 0) - { - arg = (char *) xmalloc (arglen + 1); - make_cleanup (xfree, arg); - arg[0] = 0; - for (i = 0; i < argc; i++) - { - if (i != fulltrace_arg && i != no_filters) - { - strcat (arg, argv[i]); - strcat (arg, " "); - } - } - } - else - arg = NULL; + + do_cleanups (arg_cleanup); } - } - backtrace_command_1 (arg, fulltrace_arg >= 0 /* show_locals */, - no_filters >= 0 /* no frame-filters */, from_tty); + arg = skip_spaces (arg); + if (*arg == '\0') + arg = NULL; + } - do_cleanups (old_chain); + backtrace_command_1 (arg, fulltrace /* show_locals */, + !filters /* no frame-filters */, from_tty); } /* Iterate over the local variables of a block B, calling CB with