[PATCH] [PR gdb/16238] Add completer for the show user command

[PATCH] [PR gdb/16238] Add completer for the show user command

[Lancelot SIX]

The 'show user' command (which shows the definition of non-python/scheme
user defined commands) is currently missing a completer. This is
mentioned in PR 16238.  Having one can improve the user experience.

In this commit I propose an implementation for such completer as well as
the associated tests.

Tested on x86_64 GNU/Linux.

All feedbacks are welcome.

Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16238
---
 gdb/cli/cli-cmds.c                            | 72 ++++++++++++++++++-
 .../gdb.base/show-user-completion.exp         | 72 +++++++++++++++++++
 2 files changed, 143 insertions(+), 1 deletion(-)
 create mode 100644 gdb/testsuite/gdb.base/show-user-completion.exp

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index f8f013348db..547973907fc 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1631,6 +1631,75 @@ show_user (const char *args, int from_tty)
     }
 }
 
+/* Return true if COMMAND or any of its sub-commands is a user defined command.
+   This is a helper function for show_user_completer.  */
+
+static bool
+has_user_subcmd (struct cmd_list_element *command)
+{
+  if (cli_user_command_p (command))
+    return true;
+
+  /* Alias command can yield false positive.  Ignore them as the targeted
+     command should be reachable anyway.  */
+  if (command->is_alias ())
+    return false;
+
+  if (command->is_prefix ())
+    for (struct cmd_list_element *subcommand = *command->subcommands;
+	 subcommand != nullptr;
+	 subcommand = subcommand->next)
+      if (has_user_subcmd (subcommand))
+	return true;
+
+  return false;
+}
+
+/* Implement completer for the 'show user' command.  */
+
+static void
+show_user_completer (cmd_list_element *,
+		     completion_tracker &tracker, const char *text,
+		     const char *word)
+{
+  struct cmd_list_element *cmd_group = cmdlist;
+
+  /* TEXT can contain a chain of commands and subcommands.  Follow the
+     commands chain until we reach the point where the user wants a
+     completion.  */
+  while (word > text)
+    {
+      const char *curr_cmd = text;
+      const char *after = skip_to_space (text);
+      const size_t curr_cmd_len = after - text;
+      text = skip_spaces (after);
+
+      for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
+	{
+	  if (strlen (c->name) == curr_cmd_len
+	      && strncmp (c->name, curr_cmd, curr_cmd_len) == 0)
+	    {
+	      if (c->subcommands == nullptr)
+		/* We arrived after a command with no child, so nothing more
+		   to complete.  */
+		return;
+
+	      cmd_group = *c->subcommands;
+	      break;
+	    }
+	}
+    }
+
+  const int wordlen = strlen (word);
+  for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
+    {
+      if (has_user_subcmd (c))
+	if (strncmp (c->name, word, wordlen) == 0)
+	  tracker.add_completion
+	    (gdb::unique_xmalloc_ptr<char> (xstrdup (c->name)));
+    }
+}
+
 /* Search through names of commands and documentations for a certain
    regular expression.  */
 
@@ -2596,10 +2665,11 @@ you must type \"disassemble 'foo.c'::bar\" and not \"disassemble foo.c:bar\"."))
   c = add_com ("make", class_support, make_command, _("\
 Run the ``make'' program using the rest of the line as arguments."));
   set_cmd_completer (c, filename_completer);
-  add_cmd ("user", no_class, show_user, _("\
+  c = add_cmd ("user", no_class, show_user, _("\
 Show definitions of non-python/scheme user defined commands.\n\
 Argument is the name of the user defined command.\n\
 With no argument, show definitions of all user defined commands."), &showlist);
+  set_cmd_completer (c, show_user_completer);
   add_com ("apropos", class_support, apropos_command, _("\
 Search for commands matching a REGEXP.\n\
 Usage: apropos [-v] REGEXP\n\
diff --git a/gdb/testsuite/gdb.base/show-user-completion.exp b/gdb/testsuite/gdb.base/show-user-completion.exp
new file mode 100644
index 00000000000..5468cc4d51b
--- /dev/null
+++ b/gdb/testsuite/gdb.base/show-user-completion.exp
@@ -0,0 +1,72 @@
+# Copyright 2021 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 tab-completion for the 'show user' command.
+
+load_lib completion-support.exp
+
+# This test does not require any file to be loaded.
+clean_restart
+
+# Define the 'foo' and 'bar' commands so we have something to complete.
+set re [multi_line "Type commands for definition of \"foo\"." \
+		   "End with a line saying just \"end\"." \
+		   ">$" ]
+gdb_test_multiple "define foo" "define user command: foo" {
+    -re $re {
+	gdb_test "print \"foo\"\nend" "" $gdb_test_name
+    }
+}
+
+set re [multi_line "Type commands for definition of \"bar\"." \
+		   "End with a line saying just \"end\"." \
+		   ">$"]
+gdb_test_multiple "define bar" "define user command: bar" {
+    -re  $re {
+	gdb_test "print \"bar\"\nend" "" $gdb_test_name
+    }
+}
+
+# The completer should show both options.
+test_gdb_complete_multiple "show user " "" "" "bar foo"
+
+# If we give the beginning of one of the commands, it should complete it.
+test_gdb_complete_unique "show user f" "show user foo"
+test_gdb_complete_unique "show user b" "show user bar"
+
+# Define a user prefix.
+gdb_test "define-prefix mygroup"
+
+# Add a user defined command in the user defined prefix.
+set re [multi_line  "Type commands for definition of \"mygroup mycommand\"." \
+		    "End with a line saying just \"end\"." \
+		    ">$"]
+set test_name "define user command: mygroup mycommand"
+gdb_test_multiple "define mygroup mycommand" $test_name {
+    -re  $re {
+	gdb_test "print \"42\"\nend" "" $gdb_test_name
+    }
+}
+
+with_test_prefix "with user-prefix" {
+    # We now expect the completion to yield only 3 results.  As the 'mycommand'
+    # is within the 'mygroup' prefix, it should not be reachable without
+    # traversing 'mygroup' first.
+    test_gdb_complete_multiple "show user " "" "" "bar foo mygroup"
+}
+
+# Check that we can complete commands defined under a prefix.
+test_gdb_complete_unique "show user m" "show user mygroup"
+test_gdb_complete_unique "show user mygroup " "show user mygroup mycommand"
-- 
2.33.0

Re: [PING] [PATCH] [PR gdb/16238] Add completer for the show user command

[Lancelot SIX]

Kindly pinking,

Best,
Lancelot.

On Tue, Oct 12, 2021 at 11:13:30PM +0100, Lancelot SIX wrote:
> The 'show user' command (which shows the definition of non-python/scheme
> user defined commands) is currently missing a completer. This is
> mentioned in PR 16238.  Having one can improve the user experience.
> 
> In this commit I propose an implementation for such completer as well as
> the associated tests.
> 
> Tested on x86_64 GNU/Linux.
> 
> All feedbacks are welcome.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16238
> ---
>  gdb/cli/cli-cmds.c                            | 72 ++++++++++++++++++-
>  .../gdb.base/show-user-completion.exp         | 72 +++++++++++++++++++
>  2 files changed, 143 insertions(+), 1 deletion(-)
>  create mode 100644 gdb/testsuite/gdb.base/show-user-completion.exp
> 
> diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
> index f8f013348db..547973907fc 100644
> --- a/gdb/cli/cli-cmds.c
> +++ b/gdb/cli/cli-cmds.c
> @@ -1631,6 +1631,75 @@ show_user (const char *args, int from_tty)
>      }
>  }
>  
> +/* Return true if COMMAND or any of its sub-commands is a user defined command.
> +   This is a helper function for show_user_completer.  */
> +
> +static bool
> +has_user_subcmd (struct cmd_list_element *command)
> +{
> +  if (cli_user_command_p (command))
> +    return true;
> +
> +  /* Alias command can yield false positive.  Ignore them as the targeted
> +     command should be reachable anyway.  */
> +  if (command->is_alias ())
> +    return false;
> +
> +  if (command->is_prefix ())
> +    for (struct cmd_list_element *subcommand = *command->subcommands;
> +	 subcommand != nullptr;
> +	 subcommand = subcommand->next)
> +      if (has_user_subcmd (subcommand))
> +	return true;
> +
> +  return false;
> +}
> +
> +/* Implement completer for the 'show user' command.  */
> +
> +static void
> +show_user_completer (cmd_list_element *,
> +		     completion_tracker &tracker, const char *text,
> +		     const char *word)
> +{
> +  struct cmd_list_element *cmd_group = cmdlist;
> +
> +  /* TEXT can contain a chain of commands and subcommands.  Follow the
> +     commands chain until we reach the point where the user wants a
> +     completion.  */
> +  while (word > text)
> +    {
> +      const char *curr_cmd = text;
> +      const char *after = skip_to_space (text);
> +      const size_t curr_cmd_len = after - text;
> +      text = skip_spaces (after);
> +
> +      for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
> +	{
> +	  if (strlen (c->name) == curr_cmd_len
> +	      && strncmp (c->name, curr_cmd, curr_cmd_len) == 0)
> +	    {
> +	      if (c->subcommands == nullptr)
> +		/* We arrived after a command with no child, so nothing more
> +		   to complete.  */
> +		return;
> +
> +	      cmd_group = *c->subcommands;
> +	      break;
> +	    }
> +	}
> +    }
> +
> +  const int wordlen = strlen (word);
> +  for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
> +    {
> +      if (has_user_subcmd (c))
> +	if (strncmp (c->name, word, wordlen) == 0)
> +	  tracker.add_completion
> +	    (gdb::unique_xmalloc_ptr<char> (xstrdup (c->name)));
> +    }
> +}
> +
>  /* Search through names of commands and documentations for a certain
>     regular expression.  */
>  
> @@ -2596,10 +2665,11 @@ you must type \"disassemble 'foo.c'::bar\" and not \"disassemble foo.c:bar\"."))
>    c = add_com ("make", class_support, make_command, _("\
>  Run the ``make'' program using the rest of the line as arguments."));
>    set_cmd_completer (c, filename_completer);
> -  add_cmd ("user", no_class, show_user, _("\
> +  c = add_cmd ("user", no_class, show_user, _("\
>  Show definitions of non-python/scheme user defined commands.\n\
>  Argument is the name of the user defined command.\n\
>  With no argument, show definitions of all user defined commands."), &showlist);
> +  set_cmd_completer (c, show_user_completer);
>    add_com ("apropos", class_support, apropos_command, _("\
>  Search for commands matching a REGEXP.\n\
>  Usage: apropos [-v] REGEXP\n\
> diff --git a/gdb/testsuite/gdb.base/show-user-completion.exp b/gdb/testsuite/gdb.base/show-user-completion.exp
> new file mode 100644
> index 00000000000..5468cc4d51b
> --- /dev/null
> +++ b/gdb/testsuite/gdb.base/show-user-completion.exp
> @@ -0,0 +1,72 @@
> +# Copyright 2021 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 tab-completion for the 'show user' command.
> +
> +load_lib completion-support.exp
> +
> +# This test does not require any file to be loaded.
> +clean_restart
> +
> +# Define the 'foo' and 'bar' commands so we have something to complete.
> +set re [multi_line "Type commands for definition of \"foo\"." \
> +		   "End with a line saying just \"end\"." \
> +		   ">$" ]
> +gdb_test_multiple "define foo" "define user command: foo" {
> +    -re $re {
> +	gdb_test "print \"foo\"\nend" "" $gdb_test_name
> +    }
> +}
> +
> +set re [multi_line "Type commands for definition of \"bar\"." \
> +		   "End with a line saying just \"end\"." \
> +		   ">$"]
> +gdb_test_multiple "define bar" "define user command: bar" {
> +    -re  $re {
> +	gdb_test "print \"bar\"\nend" "" $gdb_test_name
> +    }
> +}
> +
> +# The completer should show both options.
> +test_gdb_complete_multiple "show user " "" "" "bar foo"
> +
> +# If we give the beginning of one of the commands, it should complete it.
> +test_gdb_complete_unique "show user f" "show user foo"
> +test_gdb_complete_unique "show user b" "show user bar"
> +
> +# Define a user prefix.
> +gdb_test "define-prefix mygroup"
> +
> +# Add a user defined command in the user defined prefix.
> +set re [multi_line  "Type commands for definition of \"mygroup mycommand\"." \
> +		    "End with a line saying just \"end\"." \
> +		    ">$"]
> +set test_name "define user command: mygroup mycommand"
> +gdb_test_multiple "define mygroup mycommand" $test_name {
> +    -re  $re {
> +	gdb_test "print \"42\"\nend" "" $gdb_test_name
> +    }
> +}
> +
> +with_test_prefix "with user-prefix" {
> +    # We now expect the completion to yield only 3 results.  As the 'mycommand'
> +    # is within the 'mygroup' prefix, it should not be reachable without
> +    # traversing 'mygroup' first.
> +    test_gdb_complete_multiple "show user " "" "" "bar foo mygroup"
> +}
> +
> +# Check that we can complete commands defined under a prefix.
> +test_gdb_complete_unique "show user m" "show user mygroup"
> +test_gdb_complete_unique "show user mygroup " "show user mygroup mycommand"
> -- 
> 2.33.0
> 

Re: [PATCH] [PR gdb/16238] Add completer for the show user command

[Simon Marchi]

On 2021-10-12 18:13, Lancelot SIX via Gdb-patches wrote:
> The 'show user' command (which shows the definition of non-python/scheme
> user defined commands) is currently missing a completer. This is
> mentioned in PR 16238.  Having one can improve the user experience.
> 
> In this commit I propose an implementation for such completer as well as
> the associated tests.
> 
> Tested on x86_64 GNU/Linux.
> 
> All feedbacks are welcome.
> 
> Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=16238
> ---
>  gdb/cli/cli-cmds.c                            | 72 ++++++++++++++++++-
>  .../gdb.base/show-user-completion.exp         | 72 +++++++++++++++++++
>  2 files changed, 143 insertions(+), 1 deletion(-)
>  create mode 100644 gdb/testsuite/gdb.base/show-user-completion.exp
> 
> diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
> index f8f013348db..547973907fc 100644
> --- a/gdb/cli/cli-cmds.c
> +++ b/gdb/cli/cli-cmds.c
> @@ -1631,6 +1631,75 @@ show_user (const char *args, int from_tty)
>      }
>  }
>  
> +/* Return true if COMMAND or any of its sub-commands is a user defined command.
> +   This is a helper function for show_user_completer.  */
> +
> +static bool
> +has_user_subcmd (struct cmd_list_element *command)
> +{
> +  if (cli_user_command_p (command))
> +    return true;
> +
> +  /* Alias command can yield false positive.  Ignore them as the targeted
> +     command should be reachable anyway.  */
> +  if (command->is_alias ())
> +    return false;
> +
> +  if (command->is_prefix ())
> +    for (struct cmd_list_element *subcommand = *command->subcommands;
> +	 subcommand != nullptr;
> +	 subcommand = subcommand->next)
> +      if (has_user_subcmd (subcommand))
> +	return true;
> +
> +  return false;
> +}
> +
> +/* Implement completer for the 'show user' command.  */
> +
> +static void
> +show_user_completer (cmd_list_element *,
> +		     completion_tracker &tracker, const char *text,
> +		     const char *word)
> +{
> +  struct cmd_list_element *cmd_group = cmdlist;
> +
> +  /* TEXT can contain a chain of commands and subcommands.  Follow the
> +     commands chain until we reach the point where the user wants a
> +     completion.  */
> +  while (word > text)
> +    {
> +      const char *curr_cmd = text;
> +      const char *after = skip_to_space (text);
> +      const size_t curr_cmd_len = after - text;
> +      text = skip_spaces (after);
> +
> +      for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
> +	{
> +	  if (strlen (c->name) == curr_cmd_len
> +	      && strncmp (c->name, curr_cmd, curr_cmd_len) == 0)
> +	    {
> +	      if (c->subcommands == nullptr)
> +		/* We arrived after a command with no child, so nothing more
> +		   to complete.  */
> +		return;
> +
> +	      cmd_group = *c->subcommands;
> +	      break;
> +	    }
> +	}
> +    }
> +
> +  const int wordlen = strlen (word);
> +  for (struct cmd_list_element *c = cmd_group; c != nullptr; c = c->next)
> +    {
> +      if (has_user_subcmd (c))
> +	if (strncmp (c->name, word, wordlen) == 0)
> +	  tracker.add_completion
> +	    (gdb::unique_xmalloc_ptr<char> (xstrdup (c->name)));

Add curly braces for the outer "if", and the "for" doesn't need them.

Otherwise, this is OK, thanks.

Simon

Re: [PATCH] [PR gdb/16238] Add completer for the show user command

[Lancelot SIX]

> 
> Add curly braces for the outer "if", and the "for" doesn't need them.
> 
> Otherwise, this is OK, thanks.
> 
> Simon

Hi,

Thanks for the review.

I have fixed the code according to your remark and pushed this commit.

Best,
Lancelot.

Re: [PATCH] [PR gdb/16238] Add completer for the show user command

[Lancelot SIX]

Hi,

I do not have the adequate privileges to close the ticket associated
with this patch on the bug-tracker.  Could someone do it for me?

Thanks,
Lancelot.

On Sun, Nov 14, 2021 at 03:41:24PM +0000, Lancelot SIX via Gdb-patches wrote:
> > 
> > Add curly braces for the outer "if", and the "for" doesn't need them.
> > 
> > Otherwise, this is OK, thanks.
> > 
> > Simon
> 
> Hi,
> 
> Thanks for the review.
> 
> I have fixed the code according to your remark and pushed this commit.
> 
> Best,
> Lancelot.

Re: [PATCH] [PR gdb/16238] Add completer for the show user command

[Pedro Alves]

You should have now.  Please try again.

On 2021-11-19 11:35, Lancelot SIX via Gdb-patches wrote:
> Hi,
> 
> I do not have the adequate privileges to close the ticket associated
> with this patch on the bug-tracker.  Could someone do it for me?
> 
> Thanks,
> Lancelot.
> 
> On Sun, Nov 14, 2021 at 03:41:24PM +0000, Lancelot SIX via Gdb-patches wrote:
>>>
>>> Add curly braces for the outer "if", and the "for" doesn't need them.
>>>
>>> Otherwise, this is OK, thanks.
>>>
>>> Simon
>>
>> Hi,
>>
>> Thanks for the review.
>>
>> I have fixed the code according to your remark and pushed this commit.
>>
>> Best,
>> Lancelot.

Re: [PATCH] [PR gdb/16238] Add completer for the show user command

[Lancelot SIX]

Hi,

Simon did already close this ticket but is looks like I should be
able to do it now.

Thanks to both of you!
Lancelot.

On Fri, Nov 19, 2021 at 07:06:36PM +0000, Pedro Alves wrote:
> You should have now.  Please try again.
> 
> On 2021-11-19 11:35, Lancelot SIX via Gdb-patches wrote:
> > Hi,
> > 
> > I do not have the adequate privileges to close the ticket associated
> > with this patch on the bug-tracker.  Could someone do it for me?
> > 
> > Thanks,
> > Lancelot.
> > 
> > On Sun, Nov 14, 2021 at 03:41:24PM +0000, Lancelot SIX via Gdb-patches wrote:
> >>>
> >>> Add curly braces for the outer "if", and the "for" doesn't need them.
> >>>
> >>> Otherwise, this is OK, thanks.
> >>>
> >>> Simon
> >>
> >> Hi,
> >>
> >> Thanks for the review.
> >>
> >> I have fixed the code according to your remark and pushed this commit.
> >>
> >> Best,
> >> Lancelot.
>