This is the mail archive of the
gdb-patches@sourceware.org
mailing list for the GDB project.
[PATCH][TEST-CASE][DOC] Implementation of pipe to pass GDB's command output to a shell command.
- From: Abhijit Halder <abhijit dot k dot halder at gmail dot com>
- To: gdb-patches at sourceware dot org
- Date: Wed, 31 Aug 2011 20:39:30 +0530
- Subject: [PATCH][TEST-CASE][DOC] Implementation of pipe to pass GDB's command output to a shell command.
Hi all,
This is the complete patch (code in combination with documentation and
test-cases along with new-entry and change-logs) after the
incorporation of all review comments received so far. I believe the
code, test-cases and documentation part has already been approved. I
am submitting this patch as a whole for a final level of review and
approval for check-in. Please review the same and let me know whether
this version is ready for check-in.
At the same time I am working on copyright assignment. This may take a while.
Thanks,
Abhijit Halder
diff -rup src/gdb/ChangeLog dst/gdb/ChangeLog
--- src/gdb/ChangeLog 2011-08-30 19:32:29.660190911 +0530
+++ dst/gdb/ChangeLog 2011-08-30 19:35:02.000000000 +0530
@@ -1,3 +1,13 @@
+2011-08-29 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.
+
2011-08-29 Yao Qi <yao@codesourcery.com>
* solib-dsbt.c (bfd_lookup_symbol): Removed.
diff -rup src/gdb/doc/ChangeLog dst/gdb/doc/ChangeLog
--- src/gdb/doc/ChangeLog 2011-08-27 20:35:38.459934029 +0530
+++ dst/gdb/doc/ChangeLog 2011-08-31 13:33:59.000000000 +0530
@@ -1,3 +1,7 @@
+2011-08-29 Abhijit Halder <abhijit.k.halder@gmail.com>
+
+ * gdb.texinfo (Shell Commands): Add pipe command.
+
2011-08-25 Andrew Oakley <andrew@ado.is-a-geek.net>
* gdb.texinfo (Types In Python): Document 'bitpos' for enums.
diff -rup src/gdb/doc/gdb.texinfo dst/gdb/doc/gdb.texinfo
--- src/gdb/doc/gdb.texinfo 2011-08-26 21:11:39.938354007 +0530
+++ dst/gdb/doc/gdb.texinfo 2011-08-31 18:23:05.000000000 +0530
@@ -1367,6 +1367,52 @@ 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 default shell. The @var{dlim} pattern
+should not appear in @var{gdbcomd} otherwise the parsing will fail; although it
+may appear in @var{shellcmd}.
+@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 2011-08-30 19:42:53.592195665 +0530
+++ dst/gdb/Makefile.in 2011-08-30 19:42:57.000000000 +0530
@@ -714,7 +714,7 @@ 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 \
@@ -871,7 +871,7 @@ 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 2011-08-27 20:35:37.567934019 +0530
+++ dst/gdb/NEWS 2011-08-28 16:15:35.000000000 +0530
@@ -72,6 +72,9 @@
* New commands "info macros", and "info definitions" have been added.
+* 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 2011-07-29 15:15:26.078048517 +0530
+++ dst/gdb/pipe.c 2011-08-29 18:50:14.000000000 +0530
@@ -0,0 +1,230 @@
+/* Everything about pipe, for GDB.
+
+ Copyright (C) 2011 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 SHELL "cmd.exe"
+# define OPTION_TO_SHELL "/c"
+#else
+# define 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"),
+ pipe->shell_cmd);
+
+ 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)
+{
+ char *p, *t;
+ struct pipe_obj *pipe = NULL;
+ struct cleanup *cleanup;
+
+ 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;
+
+ 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"));
+
+ 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/ChangeLog dst/gdb/testsuite/ChangeLog
--- src/gdb/testsuite/ChangeLog 2011-08-27 20:35:38.871933998 +0530
+++ dst/gdb/testsuite/ChangeLog 2011-08-28 16:21:30.000000000 +0530
@@ -1,3 +1,7 @@
+2011-08-29 Abhijit Halder <abhijit.k.halder@gmail.com>
+
+ * gdb.base/pipe.exp: New file.
+
2011-08-26 Jan Kratochvil <jan.kratochvil@redhat.com>
* gdb.base/commands.exp (error_clears_commands_left): New function.
diff -rup src/gdb/testsuite/gdb.base/pipe.exp dst/gdb/testsuite/gdb.base/pipe.exp
--- src/gdb/testsuite/gdb.base/pipe.exp 2011-08-16 22:37:45.969351119 +0530
+++ dst/gdb/testsuite/gdb.base/pipe.exp 2011-08-25 03:10:05.000000000 +0530
@@ -0,0 +1,52 @@
+# Copyright 2011 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
+ regsub -all {\$[0-9]+} $fdata {} pattern
+ if ![string match $pattern " = 120 'x'\n"] then {
+ fail $test
+ } else {
+ pass $test
+ }
+}