[RFA,1/4] Implement user defined prefix.

Message ID 20190929205427.1319-2-philippe.waroquiers@skynet.be
State New
Headers show
Series
  • More flexible user-defined commands prefixing and naming.
Related show

Commit Message

Philippe Waroquiers Sept. 29, 2019, 8:54 p.m.
This patch adds the new 'prefix-define' command that creates (or mark an
existing user defined command) as a prefix command.
This approach was preferred compared to add a -prefix option to
'define' command : with prefix-define, a command can be defined and
afterwards marked as a prefix.  Also, it is easier to define a
'prefix' only command in one operation.

This patch also adds completers for the 'define' and 'document' commands.
This makes it easier for the user to type the prefixes for 'define'
and type the documented command name for 'document'.

gdb/ChangeLog
YYYY-MM-DD  Philippe Waroquiers  <philippe.waroquiers@skynet.be>

	* cli/cli-script.c (do_define_command): Ensure a redefined
	prefix command is kept as a prefix command.
	(prefix_define_command): New function.
	(show_user_1): Report user defined prefixes.
	(_initialize_cli_script):  Create the new 'prefix-define' command.
	Add completers for 'define' and 'document'.
	* top.c (execute_command):  If command is a user-defined prefix only
	command, report the list of commands for this prefix command.
---
 gdb/cli/cli-script.c | 107 +++++++++++++++++++++++++++++++++++++------
 gdb/top.c            |  10 ++++
 2 files changed, 103 insertions(+), 14 deletions(-)

-- 
2.20.1

Comments

Eli Zaretskii Sept. 30, 2019, 6:03 a.m. | #1
> From: Philippe Waroquiers <philippe.waroquiers@skynet.be>

> Cc: Philippe Waroquiers <philippe.waroquiers@skynet.be>

> Date: Sun, 29 Sep 2019 22:54:24 +0200

> 

> +  set_cmd_completer (define_cmd_element, command_completer);

> +  c = add_com ("prefix-define", class_support, prefix_define_command,

> +	   _("\

> +Define or mark a command as a user-defined prefix command.\n\

> +User defined prefix commands can be used as prefix commands for\n\

> +other user defined commands.\n\


I suggest to use "user-defined" consistently, with a hyphen.

Patch

diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 4fc9c70259..c70c0e4fb3 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -29,6 +29,7 @@ 
 #include "cli/cli-cmds.h"
 #include "cli/cli-decode.h"
 #include "cli/cli-script.h"
+#include "cli/cli-style.h"
 
 #include "extension.h"
 #include "interps.h"
@@ -1444,10 +1445,22 @@  do_define_command (const char *comname, int from_tty,
   else
     cmds = *commands;
 
-  newc = add_cmd (comname, class_user, user_defined_command,
-		  (c && c->theclass == class_user)
-		  ? c->doc : xstrdup ("User-defined."), list);
-  newc->user_commands = std::move (cmds);
+  {
+    struct cmd_list_element **c_prefixlist = c ? c->prefixlist : nullptr;
+    const char *c_prefixname = c ? c->prefixname : nullptr;
+
+    newc = add_cmd (comname, class_user, user_defined_command,
+		    (c && c->theclass == class_user)
+		    ? c->doc : xstrdup ("User-defined."), list);
+    newc->user_commands = std::move (cmds);
+
+    if (c_prefixlist != nullptr)
+      {
+	newc->prefixlist = c_prefixlist;
+	newc->prefixname = c_prefixname;
+	newc->allow_unknown = newc->user_commands.get () != nullptr;
+    }
+  }
 
   /* If this new command is a hook, then mark both commands as being
      tied.  */
@@ -1522,6 +1535,52 @@  document_command (const char *comname, int from_tty)
     c->doc = doc;
   }
 }
+
+/* Implementation of the "prefix-define" command.  */
+
+static void
+prefix_define_command (const char *comname, int from_tty)
+{
+  struct cmd_list_element *c, **list;
+  const char *tem;
+  const char *comfull;
+  char *prefixname;
+
+  comfull = comname;
+  list = validate_comname (&comname);
+
+  /* Look it up, and verify that we got an exact match.  */
+  tem = comname;
+  c = lookup_cmd (&tem, *list, "", -1, 1);
+  if (c && strcmp (comname, c->name) != 0)
+    c = nullptr;
+
+  if (c && c->theclass != class_user)
+    error (_("Command \"%s\" is built-in."), comfull);
+
+  if (c && c->prefixlist != nullptr)
+    {
+      /* c is already a user defined prefix command.  */
+      return;
+    }
+
+  if (c == nullptr)
+    {
+      comname = xstrdup (comname);
+      c = add_cmd (comname, class_user, user_defined_command,
+		   xstrdup ("User-defined."), list);
+    }
+
+  c->prefixlist = new struct cmd_list_element*;
+  *(c->prefixlist) = nullptr;
+  prefixname = (char *) xmalloc (strlen (comfull) + 2);
+  prefixname[0] = 0;
+  strcat (prefixname, comfull);
+  strcat (prefixname, " ");
+  c->prefixname = prefixname;
+  c->allow_unknown = c->user_commands.get () != nullptr;
+}
+
 
 /* Used to implement source_command.  */
 
@@ -1562,7 +1621,21 @@  void
 show_user_1 (struct cmd_list_element *c, const char *prefix, const char *name,
 	     struct ui_file *stream)
 {
-  struct command_line *cmdlines;
+  if (cli_user_command_p (c))
+    {
+      struct command_line *cmdlines = c->user_commands.get ();
+
+      fprintf_filtered (stream, "User %scommand \"",
+			c->prefixlist == NULL ? "" : "prefix ");
+      fprintf_styled (stream, title_style.style (), "%s%s",
+		      prefix, name);
+      fprintf_filtered (stream, "\":\n");
+      if (cmdlines)
+	{
+	  print_command_lines (current_uiout, cmdlines, 1);
+	  fputs_filtered ("\n", stream);
+	}
+    }
 
   if (c->prefixlist != NULL)
     {
@@ -1571,25 +1644,23 @@  show_user_1 (struct cmd_list_element *c, const char *prefix, const char *name,
       for (c = *c->prefixlist; c != NULL; c = c->next)
 	if (c->theclass == class_user || c->prefixlist != NULL)
 	  show_user_1 (c, prefixname, c->name, gdb_stdout);
-      return;
     }
 
-  cmdlines = c->user_commands.get ();
-  fprintf_filtered (stream, "User command \"%s%s\":\n", prefix, name);
-
-  if (!cmdlines)
-    return;
-  print_command_lines (current_uiout, cmdlines, 1);
-  fputs_filtered ("\n", stream);
 }
 
 void
 _initialize_cli_script (void)
 {
-  add_com ("document", class_support, document_command, _("\
+  struct cmd_list_element *c;
+
+  /* "document", "define" and "prefix-define" use command_completer,
+     as this helps the user to either type the command name and/or
+     its prefixes.  */
+  c = add_com ("document", class_support, document_command, _("\
 Document a user-defined command.\n\
 Give command name as argument.  Give documentation on following lines.\n\
 End with a line of just \"end\"."));
+  set_cmd_completer (c, command_completer);
   define_cmd_element = add_com ("define", class_support, define_command, _("\
 Define a new command name.  Command name is argument.\n\
 Definition appears on following lines, one command per line.\n\
@@ -1598,6 +1669,14 @@  Use the \"document\" command to give documentation for the new command.\n\
 Commands defined in this way may accept an unlimited number of arguments\n\
 accessed via $arg0 .. $argN.  $argc tells how many arguments have\n\
 been passed."));
+  set_cmd_completer (define_cmd_element, command_completer);
+  c = add_com ("prefix-define", class_support, prefix_define_command,
+	   _("\
+Define or mark a command as a user-defined prefix command.\n\
+User defined prefix commands can be used as prefix commands for\n\
+other user defined commands.\n\
+If the command already exists, it is changed to a prefix command."));
+  set_cmd_completer (c, command_completer);
 
   while_cmd_element = add_com ("while", class_support, while_command, _("\
 Execute nested commands WHILE the conditional expression is non zero.\n\
diff --git a/gdb/top.c b/gdb/top.c
index a1a08e0b99..abd07bd6fe 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -615,6 +615,16 @@  execute_command (const char *p, int from_tty)
       /* c->user_commands would be NULL in the case of a python command.  */
       if (c->theclass == class_user && c->user_commands)
 	execute_user_command (c, arg);
+      else if (c->theclass == class_user
+	       && c->prefixlist && !c->allow_unknown)
+	/* If this is a user defined prefix that does not allow unknown,
+	   report the list of subcommands.  */
+	{
+	  printf_unfiltered
+	    ("\"%.*s\" must be followed by the name of an %s command.\n",
+	     (int) strlen (c->prefixname) - 1, c->prefixname, c->name);
+	  help_list (*c->prefixlist, c->prefixname, all_commands, gdb_stdout);
+	}
       else if (c->type == set_cmd)
 	do_set_command (arg, from_tty, c);
       else if (c->type == show_cmd)