From: Abhijit Halder <abhijit.k.halder@gmail.com>
To: "gdb-patches@sourceware.org ml" <gdb-patches@sourceware.org>
Subject: Re: [PATCH] Implementation of pipe to pass GDB's command output to the shell.
Date: Fri, 06 Jan 2012 18:11:00 -0000 [thread overview]
Message-ID: <CAOhZP9ztj5wEyxH6qs-vMAdwtv=qgnH789+hm0CfrcdWfMDY7w@mail.gmail.com> (raw)
In-Reply-To: <CAOhZP9xyU9QkK21-saccqhdKBrQicCmAKsbRR18xWGJRjEipvw@mail.gmail.com>
[-- Attachment #1: Type: text/plain, Size: 1069 bytes --]
On Tue, Jan 3, 2012 at 10:34 PM, Abhijit Halder
<abhijit.k.halder@gmail.com> wrote:
> Hi all,
>
> The copyright assignment is yet to be accomplished, it's almost in
> final stage. Meanwhile I want you to please do a final review of the
> changes I made.
>
> This patch implements a new gdb command namely, "pipe" to pass gdb
> command output to a shell command for further processing. This patch
> includes necessary documentation change and test-cases as well.
>
> Thanks,
> Abhijit Halder
One last minute correction.
>+/* Run execute_command for PIPE and FROM_TTY. Write output to the pipe, do not
>+ display it to the screen. */
>+
>+static void
>+execute_command_to_pipe (struct pipe_obj *pipe, int from_tty)
>+{
>+ char *argv[4];
>+ struct cleanup *cleanup;
>+ struct ui_file *fp;
>+ int status;
>+ const char *errmsg;
>+ volatile struct gdb_exception exception;
>+ const char *shell;
Thie following correction is required to fix compilation error.
char *shell;
>+
>+ if (*pipe->gdb_cmd == '\0')
>+ error (_("No gdb-command is specified."));
>+
[-- Attachment #2: ChangeLog.txt --]
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2012-01-03 Abhijit Halder <abhijit.k.halder@gmail.com>
Implementation of pipe to pass GDB's command output to a shell
command for processing.
* NEWS: Add news item for the new command "pipe".
* pipe.c: New file.
* Makefile.in (SFILES): Add pipe.c.
(COMMON_OBS): Add pipe.o.
[-- Attachment #3: gdb-pipecmd-new.patch --]
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diff -rup src/gdb/doc/gdb.texinfo dst/gdb/doc/gdb.texinfo
--- src/gdb/doc/gdb.texinfo 2012-01-06 14:46:43.881568021 +0530
+++ dst/gdb/doc/gdb.texinfo 2012-01-06 15:59:08.945568207 +0530
@@ -1367,6 +1367,56 @@ Execute the @code{make} program with the
arguments. This is equivalent to @samp{shell make @var{make-args}}.
@end table
+If you want to process the output of a @value{GDBN} command using some shell
+command or some script, that can be done by using the command @code{pipe}.
+
+@table @code
+@kindex pipe
+@item pipe @var{dlim} @var{gdbcmd} @var{dlim} @var{shellcmd}
+@var{dlim} is a string of arbitrary length, containing no whitespace and no
+leading @samp{-}, acts as a separator between a @value{GDBN} command
+@var{gdbcmd} and a shell command @var{shellcmd}. The shell command should be
+in compliance with the syntax of the shell. The @var{dlim} pattern should not
+appear in @var{gdbcomd}, otherwise the parsing will fail; although it may
+appear in @var{shellcmd}.
+
+If exists, the environment variable @code{SHELL} determines in which shell to
+run the shell command. Otherwise @value{GDBN} uses the default shell
+(@file{/bin/sh} on Unix systems, @file{COMMAND.COM} on MS-DOS, etc.).
+@end table
+
+@smallexample
+(@value{GDBP}) @b{ptype dd_tbl}
+type = struct dd @{
+ int dd_handle;
+ const char *dd_name;
+ int dd_major;
+ int dd_minor;
+ void *dd_code;
+ void *dd_data;
+@} [1024]
+(@value{GDBP}) @b{pipe <br> print dd_tbl <br> sed 's/@}/\n/g' | grep @
+"\.test_dd" | tr ',' '\n'}
+
+ @{dd_handle = 10
+ dd_name = 0x8048538 ".test_dd"
+ dd_major = 100
+ dd_minor = 0
+ dd_code = 0xcc
+ dd_data = 0x80
+@end smallexample
+
+In the above example @samp{<br>} acts as a delimiter. The output of
+@samp{print dd_tbl} is passed to the shell command @samp{sed 's/@}/\n/g' | @
+grep ".test_dd" | tr ',' '\n'} for processing. @samp{|} could be one of the
+natural choise of being used as the delimiter. In the above example we have
+avoided the same for readability purpose.
+
+In the given example the output of @value{GDBN} command @samp{print dd_tbl} is
+huge and not well formated. The use of shell commands like @command{sed},
+@command{tr} and @command{grep} ease the searching of desired pattern and hence
+ease debugging.
+
@node Logging Output
@section Logging Output
@cindex logging @value{GDBN} output
diff -rup src/gdb/Makefile.in dst/gdb/Makefile.in
--- src/gdb/Makefile.in 2012-01-06 15:48:37.405568350 +0530
+++ dst/gdb/Makefile.in 2012-01-06 15:59:08.945568207 +0530
@@ -718,7 +718,7 @@ SFILES = ada-exp.y ada-lang.c ada-typepr
objc-exp.y objc-lang.c \
objfiles.c osabi.c observer.c osdata.c \
opencl-lang.c \
- p-exp.y p-lang.c p-typeprint.c p-valprint.c parse.c printcmd.c \
+ p-exp.y p-lang.c p-typeprint.c p-valprint.c parse.c pipe.c printcmd.c \
proc-service.list progspace.c \
prologue-value.c psymtab.c \
regcache.c reggroups.c remote.c remote-fileio.c reverse.c \
@@ -875,7 +875,7 @@ COMMON_OBS = $(DEPFILES) $(CONFIG_OBS) $
mi-common.o \
event-loop.o event-top.o inf-loop.o completer.o \
gdbarch.o arch-utils.o gdbtypes.o osabi.o copying.o \
- memattr.o mem-break.o target.o parse.o language.o buildsym.o \
+ memattr.o mem-break.o target.o parse.o pipe.o language.o buildsym.o \
findcmd.o \
std-regs.o \
signals.o \
diff -rup src/gdb/NEWS dst/gdb/NEWS
--- src/gdb/NEWS 2012-01-03 19:38:09.721001462 +0530
+++ dst/gdb/NEWS 2012-01-06 15:59:08.945568207 +0530
@@ -138,6 +138,9 @@
"!" is now an alias of the "shell" command.
Note that no space is needed between "!" and SHELL COMMAND.
+* New command "pipe" has been added to make GDB's command output available to a
+ shell command for processing.
+
* Changed commands
watch EXPRESSION mask MASK_VALUE
diff -rup src/gdb/pipe.c dst/gdb/pipe.c
--- src/gdb/pipe.c 2012-01-06 15:48:14.917568019 +0530
+++ dst/gdb/pipe.c 2012-01-06 15:59:08.945568207 +0530
@@ -0,0 +1,239 @@
+/* Everything about pipe command, for GDB.
+
+ Copyright (C) 2012 Free Software Foundation, Inc.
+
+ This file is part of GDB.
+
+ 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 <http://www.gnu.org/licenses/>. */
+
+#include "defs.h"
+#include <ctype.h>
+#include "gdb_string.h"
+#include "ui-file.h"
+#include "ui-out.h"
+#include "cli/cli-utils.h"
+#include "gdbcmd.h"
+#include "libiberty.h"
+#include "exceptions.h"
+
+#if defined (__MINGW32__)
+# define DEFAULT_SHELL "cmd.exe"
+# define OPTION_TO_SHELL "/c"
+#else
+# define DEFAULT_SHELL "/bin/sh"
+# define OPTION_TO_SHELL "-c"
+#endif
+
+/* Structure to encapsulate all entities associated with pipe. */
+
+struct pipe_obj
+{
+ /* The delimiter to separate out gdb-command and shell-command. This can be
+ any arbitrary string without containing any whitespace. There should not
+ be any leading '-' in the delimiter. */
+ char *dlim;
+
+ /* The gdb-command. */
+ char *gdb_cmd;
+
+ /* The shell-command. */
+ char *shell_cmd;
+
+ /* The gdb-side stream pointer to the pipe. */
+ FILE *handle;
+
+ /* The pex object used to create pipeline between gdb and shell. */
+ struct pex_obj *pex;
+};
+
+/* Destruct pipe object referenced by ARG. */
+
+static void
+destruct_pipe (void *arg)
+{
+ struct pipe_obj *pipe = (struct pipe_obj *) arg;
+
+ if (pipe->handle != NULL)
+ fclose (pipe->handle);
+
+ if (pipe->pex != NULL)
+ {
+ int status;
+
+ /* Wait till the process on the other side of the pipe completes its
+ job before closing its file descriptors. */
+ pex_get_status (pipe->pex, 1, &status);
+
+ if (!WIFEXITED (status))
+ warning (_("Execution of shell-command `%s' may not be completed: %s."),
+ pipe->shell_cmd, safe_strerror (status));
+
+ pex_free (pipe->pex);
+ }
+
+ xfree (pipe->dlim);
+ xfree (pipe);
+}
+
+/* Construct a pipe object by parsing argument ARG to the pipe command. */
+
+static struct pipe_obj *
+construct_pipe (const char *arg)
+{
+ struct pipe_obj *pipe;
+ struct cleanup *cleanup;
+ char *p, *t;
+
+ if (arg == NULL)
+ error (_("No argument is specified."));
+
+ pipe = XCNEW (struct pipe_obj);
+ cleanup = make_cleanup (destruct_pipe, pipe);
+
+ p = xstrdup (arg);
+ pipe->dlim = p;
+
+ if (*pipe->dlim == '-')
+ error (_("Delimiter pattern should not start with `-'."));
+
+ t = skip_to_space (p);
+ p = skip_spaces (t);
+
+ if (*p == '\0')
+ error (_("No gdb-command is specified."));
+
+ *t = '\0';
+ pipe->gdb_cmd = p;
+
+ for (;;)
+ {
+ t = skip_to_space (p);
+
+ if (*t == '\0')
+ error (_("No shell-command is specified."));
+
+ /* Check whether the token separated by whitespace matches with
+ delimiter. */
+ if (memcmp (p, pipe->dlim, (t - p)) == 0
+ && pipe->dlim[t - p] == '\0')
+ {
+ *p = '\0';
+ pipe->shell_cmd = skip_spaces (t);
+ break;
+ }
+
+ p = skip_spaces (t);
+ }
+
+ discard_cleanups (cleanup);
+ return pipe;
+}
+
+/* Run execute_command for PIPE and FROM_TTY. Write output to the pipe, do not
+ display it to the screen. */
+
+static void
+execute_command_to_pipe (struct pipe_obj *pipe, int from_tty)
+{
+ char *argv[4];
+ struct cleanup *cleanup;
+ struct ui_file *fp;
+ int status;
+ const char *errmsg;
+ volatile struct gdb_exception exception;
+ char *shell;
+
+ if (*pipe->gdb_cmd == '\0')
+ error (_("No gdb-command is specified."));
+
+ /* Figure out what shell the user program is under. */
+ shell = getenv ("SHELL");
+ if (shell == NULL)
+ shell = DEFAULT_SHELL;
+
+ argv[0] = shell;
+ argv[1] = OPTION_TO_SHELL;
+ argv[2] = pipe->shell_cmd;
+ argv[3] = NULL;
+
+ pipe->pex = pex_init (PEX_USE_PIPES, argv[0], NULL);
+ pipe->handle = pex_input_pipe (pipe->pex, 0);
+
+ if (pipe->handle == NULL)
+ error (_("Failed to create pipe: %s."), safe_strerror (errno));
+
+ errmsg = pex_run (pipe->pex, PEX_LAST, argv[0], argv, NULL, NULL, &status);
+
+ if (errmsg != NULL)
+ error (_("Failed to execute shell-command `%s' on pipe: %s: %s."),
+ pipe->shell_cmd, errmsg, safe_strerror (status));
+
+ /* GDB_STDOUT should be better already restored during these
+ restoration callbacks. */
+ cleanup = set_batch_flag_and_make_cleanup_restore_page_info ();
+ fp = stdio_fileopen (pipe->handle);
+ make_cleanup_ui_file_delete (fp);
+ make_cleanup_restore_ui_file (&gdb_stdout);
+ make_cleanup_restore_ui_file (&gdb_stderr);
+ make_cleanup_restore_ui_file (&gdb_stdlog);
+ make_cleanup_restore_ui_file (&gdb_stdtarg);
+ make_cleanup_restore_ui_file (&gdb_stdtargerr);
+
+ if (ui_out_redirect (current_uiout, fp) < 0)
+ warning (_("Current output protocol does not support redirection"));
+ else
+ make_cleanup_ui_out_redirect_pop (current_uiout);
+
+ gdb_stdout = fp;
+ gdb_stderr = fp;
+ gdb_stdlog = fp;
+ gdb_stdtarg = fp;
+ gdb_stdtargerr = fp;
+
+ TRY_CATCH (exception, RETURN_MASK_ERROR)
+ {
+ execute_command (pipe->gdb_cmd, from_tty);
+ }
+
+ if (exception.reason < 0)
+ exception_print (gdb_stderr, exception);
+
+ do_cleanups (cleanup);
+}
+
+/* Execute the pipe command with argument ARG and FROM_TTY. */
+
+static void
+pipe_command (char *arg, int from_tty)
+{
+ struct pipe_obj *pipe = construct_pipe (arg);
+ struct cleanup *cleanup = make_cleanup (destruct_pipe, pipe);
+
+ execute_command_to_pipe (pipe, from_tty);
+ do_cleanups (cleanup);
+}
+
+/* Module initialization. */
+
+void
+_initialize_pipe (void)
+{
+ add_cmd ("pipe", no_class, pipe_command, _("\
+Create pipe to pass gdb-command output to a shell command for processing.\n\
+Arguments are a delimiter, followed by a gdb-command, then the same\n\
+delimiter again and finally a shell-command.\n\n\
+The delimiter can be a string of arbitrary length containing no whitespace\n\
+and should not have any leading `-'."),
+ &cmdlist);
+}
diff -rup src/gdb/testsuite/gdb.base/pipe.exp dst/gdb/testsuite/gdb.base/pipe.exp
--- src/gdb/testsuite/gdb.base/pipe.exp 2011-09-13 16:37:04.294277252 +0530
+++ dst/gdb/testsuite/gdb.base/pipe.exp 2012-01-06 15:59:08.945568207 +0530
@@ -0,0 +1,51 @@
+# Copyright 2012 Free Software Foundation, Inc.
+
+# 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 <http://www.gnu.org/licenses/>.
+
+#
+# test gdb pipe commands
+#
+
+set test "pipe"
+set tempfile ${objdir}/${subdir}/${test}.x
+
+gdb_exit
+gdb_start
+
+gdb_test "pipe" "No argument is specified"
+gdb_test "pipe |" "No gdb-command is specified"
+gdb_test "pipe -x" "Delimiter pattern should not start with '-'"
+gdb_test "pipe | print 'x'" "No shell-command is specified"
+gdb_test "pipe | print 'x' |< cat" "No shell-command is specified"
+gdb_test "pipe |< print 'x' | cat" "No shell-command is specified"
+gdb_test "pipe | print 'x' >| cat" "No shell-command is specified"
+gdb_test "pipe >| print 'x' | cat" "No shell-command is specified"
+gdb_test "pipe | print 'x' | cat" " = 120 'x'"
+gdb_test "pipe | print 'x' | cat | cat" " = 120 'x'"
+
+file delete $tempfile
+gdb_test_no_output "pipe | p 'x' | cat >$tempfile"
+if ![file exists $tempfile] then {
+ perror "$tempfile does not exist."
+ return 0
+} else {
+ set fp [open $tempfile r]
+ set fdata [read $fp]
+ close $fp
+ if ![regexp {^\$[0-9]+ = 120 'x'\n$} $fdata] then {
+ fail $test
+ } else {
+ pass $test
+ }
+}
[-- Attachment #4: doc-ChangeLog.txt --]
[-- Type: text/plain, Size: 109 bytes --]
2012-01-03 Abhijit Halder <abhijit.k.halder@gmail.com>
* gdb.texinfo (Shell Commands): Add pipe command.
[-- Attachment #5: testsuite-ChangeLog.txt --]
[-- Type: text/plain, Size: 90 bytes --]
2011-08-29 Abhijit Halder <abhijit.k.halder@gmail.com>
* gdb.base/pipe.exp: New file.
next prev parent reply other threads:[~2012-01-06 18:11 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-03 17:04 Abhijit Halder
2012-01-06 18:11 ` Abhijit Halder [this message]
2012-01-07 18:19 ` Sergio Durigan Junior
2012-01-08 6:57 ` Abhijit Halder
2012-01-08 7:17 ` Sergio Durigan Junior
2012-01-08 7:27 ` Abhijit Halder
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