[PATCH 1/7] new observer command_option_changed.

[Yao Qi <yao@codesourcery.com>]

Hi,
This patch is to add an extra field 'notify_observer_p' to identify
the command will notify observer 'command_option_changed', and teach
GDB to check the change of command option, and notify observer.

Compared with V1, V2 has following changes,
  1.  Move notifying 'command_option_changed' observer out of
do_setshow_command to its caller, execute_command, so that we can
get the full command line to send MI notification for multi-word
options.
  2.  Split do_setshow_command to do_set_command and do_show_command.

Note that in order to make patch easier to read, the indnetation is
not adjusted.  Indentation is fixed in a separate patch.

gdb:

2012-07-27  Yao Qi  <yao@codesourcery.com>

	* cli/cli-decode.c (add_cmd): Set field 'notify_observer_p' to 0.
	(add_setshow_auto_boolean_cmd): Move auto_boolean_enums out.
	Remove 'static'.
	* cli/cli-decode.h (struct cmd_list_element) <notify_observer_p>:
	New field.
	Declare 'auto_boolean_enums'.
	* cli/cli-setshow.c (do_setshow_command): Split it to ...
	(do_set_command, do_show_command): ... them.  New.
	(cmd_show_list): Caller update.
	* auto-load.c (set_auto_load_cmd): Likewise.
	* remote.c (show_remote_cmd): Likewise.
	* cli/cli-setshow.h: Update declarations.
	* top.c (execute_command): Call do_set_command and
	call observer_notify_command_option_changed if it return true.

gdb/doc:

2012-07-27  Yao Qi  <yao@codesourcery.com>

	* observer.texi: New observer command_option_changed.
---
 gdb/auto-load.c       |    2 +-
 gdb/cli/cli-decode.c  |    4 +-
 gdb/cli/cli-decode.h  |    4 +
 gdb/cli/cli-setshow.c |  164 ++++++++++++++++++++++++++++++++++++------------
 gdb/cli/cli-setshow.h |   10 +--
 gdb/doc/observer.texi |    8 +++
 gdb/remote.c          |    2 +-
 gdb/top.c             |   22 ++++++-
 8 files changed, 163 insertions(+), 53 deletions(-)

diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index 87dd1e4..471a8a7 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -1024,7 +1024,7 @@ set_auto_load_cmd (char *args, int from_tty)
     if (list->var_type == var_boolean)
       {
 	gdb_assert (list->type == set_cmd);
-	do_setshow_command (args, from_tty, list);
+	do_set_command (args, from_tty, list);
       }
 }
 
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index c337b43..35c7e1e 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -203,6 +203,7 @@ add_cmd (char *name, enum command_class class, void (*fun) (char *, int),
   c->user_commands = NULL;
   c->cmd_pointer = NULL;
   c->alias_chain = NULL;
+  c->notify_observer_p = 0;
 
   return c;
 }
@@ -430,6 +431,8 @@ add_setshow_enum_cmd (char *name,
   c->enums = enumlist;
 }
 
+const char * const auto_boolean_enums[] = { "on", "off", "auto", NULL };
+
 /* Add an auto-boolean command named NAME to both the set and show
    command list lists.  CLASS is as in add_cmd.  VAR is address of the
    variable which will contain the value.  DOC is the documentation
@@ -445,7 +448,6 @@ add_setshow_auto_boolean_cmd (char *name,
 			      struct cmd_list_element **set_list,
 			      struct cmd_list_element **show_list)
 {
-  static const char *auto_boolean_enums[] = { "on", "off", "auto", NULL };
   struct cmd_list_element *c;
 
   add_setshow_cmd_full (name, class, var_auto_boolean, var,
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index b5e0790..ae5d0a1 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -210,6 +210,9 @@ struct cmd_list_element
 
     /* Link pointer for aliases on an alias list.  */
     struct cmd_list_element *alias_chain;
+
+    /* Notify 'command_option_changed' observer if it is true.  */
+    int notify_observer_p;
   };
 
 extern void help_cmd_list (struct cmd_list_element *, enum command_class,
@@ -232,5 +235,6 @@ extern void not_just_help_class_command (char *arg, int from_tty);
 
 extern void print_doc_line (struct ui_file *, char *);
 
+extern const char * const auto_boolean_enums[];
 
 #endif /* !defined (CLI_DECODE_H) */
diff --git a/gdb/cli/cli-setshow.c b/gdb/cli/cli-setshow.c
index 7ffb89e..17c336e 100644
--- a/gdb/cli/cli-setshow.c
+++ b/gdb/cli/cli-setshow.c
@@ -116,18 +116,20 @@ deprecated_show_value_hack (struct ui_file *ignore_file,
     }
 }
 
-/* Do a "set" or "show" command.  ARG is NULL if no argument, or the
+/* Do a "set" command.  ARG is NULL if no argument, or the
    text of the argument, and FROM_TTY is nonzero if this command is
    being entered directly by the user (i.e. these are just like any
-   other command).  C is the command list element for the command.  */
+   other command).  C is the command list element for the command.  Return
+   true if command option is changed, otherwise return false.  */
 
-void
-do_setshow_command (char *arg, int from_tty, struct cmd_list_element *c)
+int
+do_set_command (char *arg, int from_tty, struct cmd_list_element *c)
 {
-  struct ui_out *uiout = current_uiout;
+  /* A flag to indicate the option is changed or not.  */
+  int option_changed = 0;
+
+  gdb_assert (c->type == set_cmd);
 
-  if (c->type == set_cmd)
-    {
       switch (c->var_type)
 	{
 	case var_string:
@@ -170,50 +172,106 @@ do_setshow_command (char *arg, int from_tty, struct cmd_list_element *c)
 #endif
 	    *q++ = '\0';
 	    new = (char *) xrealloc (new, q - new);
-	    xfree (*(char **) c->var);
-	    *(char **) c->var = new;
+
+	    if (*(char **) c->var == NULL
+		|| strcmp (*(char **) c->var, new) != 0)
+	      {
+		xfree (*(char **) c->var);
+		*(char **) c->var = new;
+
+		option_changed = 1;
+	      }
+	    else
+	      xfree (new);
 	  }
 	  break;
 	case var_string_noescape:
 	  if (arg == NULL)
 	    arg = "";
-	  xfree (*(char **) c->var);
-	  *(char **) c->var = xstrdup (arg);
+
+	  if (*(char **) c->var == NULL || strcmp (*(char **) c->var, arg) != 0)
+	    {
+	      xfree (*(char **) c->var);
+	      *(char **) c->var = xstrdup (arg);
+
+	      option_changed = 1;
+	    }
 	  break;
 	case var_filename:
 	  if (arg == NULL)
 	    error_no_arg (_("filename to set it to."));
 	  /* FALLTHROUGH */
 	case var_optional_filename:
-	  xfree (*(char **) c->var);
+	  {
+	    char *val = NULL;
 
-	  if (arg != NULL)
-	    {
-	      /* Clear trailing whitespace of filename.  */
-	      char *ptr = arg + strlen (arg) - 1;
+	    if (arg != NULL)
+	      {
+		/* Clear trailing whitespace of filename.  */
+		char *ptr = arg + strlen (arg) - 1;
 
-	      while (ptr >= arg && (*ptr == ' ' || *ptr == '\t'))
-		ptr--;
-	      *(ptr + 1) = '\0';
+		while (ptr >= arg && (*ptr == ' ' || *ptr == '\t'))
+		  ptr--;
+		*(ptr + 1) = '\0';
 
-	      *(char **) c->var = tilde_expand (arg);
-	    }
-	  else
-	    *(char **) c->var = xstrdup ("");
+		val = tilde_expand (arg);
+	      }
+	    else
+	      val = xstrdup ("");
+
+	    if (*(char **) c->var == NULL
+		|| strcmp (*(char **) c->var, val) != 0)
+	      {
+		xfree (*(char **) c->var);
+		*(char **) c->var = val;
+
+		option_changed = 1;
+	      }
+	    else
+	      xfree (val);
+	  }
 	  break;
 	case var_boolean:
-	  *(int *) c->var = parse_binary_operation (arg);
+	  {
+	    int val = parse_binary_operation (arg);
+
+	    if (val != *(int *) c->var)
+	      {
+		*(int *) c->var = val;
+
+		option_changed = 1;
+	      }
+	  }
 	  break;
 	case var_auto_boolean:
-	  *(enum auto_boolean *) c->var = parse_auto_binary_operation (arg);
+	  {
+	    enum auto_boolean val = parse_auto_binary_operation (arg);
+
+	    if (*(enum auto_boolean *) c->var != val)
+	      {
+		*(enum auto_boolean *) c->var = val;
+
+		option_changed = 1;
+	      }
+	  }
 	  break;
 	case var_uinteger:
 	case var_zuinteger:
 	  if (arg == NULL)
 	    error_no_arg (_("integer to set it to."));
-	  *(unsigned int *) c->var = parse_and_eval_long (arg);
-	  if (c->var_type == var_uinteger && *(unsigned int *) c->var == 0)
-	    *(unsigned int *) c->var = UINT_MAX;
+	  {
+	    unsigned int val = parse_and_eval_long (arg);
+
+	    if (c->var_type == var_uinteger && val == 0)
+	      val = UINT_MAX;
+
+	    if (*(unsigned int *) c->var != val)
+	      {
+		*(unsigned int *) c->var = val;
+
+		option_changed = 1;
+	      }
+	  }
 	  break;
 	case var_integer:
 	case var_zinteger:
@@ -224,11 +282,17 @@ do_setshow_command (char *arg, int from_tty, struct cmd_list_element *c)
 	      error_no_arg (_("integer to set it to."));
 	    val = parse_and_eval_long (arg);
 	    if (val == 0 && c->var_type == var_integer)
-	      *(int *) c->var = INT_MAX;
+	      val = INT_MAX;
 	    else if (val >= INT_MAX)
 	      error (_("integer %u out of range"), val);
-	    else
-	      *(int *) c->var = val;
+
+
+	    if (*(int *) c->var != val)
+	      {
+		*(int *) c->var = val;
+
+		option_changed = 1;
+	      }
 	    break;
 	  }
 	case var_enum:
@@ -293,15 +357,36 @@ do_setshow_command (char *arg, int from_tty, struct cmd_list_element *c)
 	    if (nmatches > 1)
 	      error (_("Ambiguous item \"%s\"."), arg);
 
-	    *(const char **) c->var = match;
+	    if (*(const char **) c->var != match)
+	      {
+		*(const char **) c->var = match;
+
+		option_changed = 1;
+	      }
 	  }
 	  break;
 	default:
 	  error (_("gdb internal error: bad var_type in do_setshow_command"));
 	}
-    }
-  else if (c->type == show_cmd)
-    {
+      c->func (c, NULL, from_tty);
+      if (deprecated_set_hook)
+	deprecated_set_hook (c);
+
+  return option_changed;
+}
+
+/* Do a "show" command.  ARG is NULL if no argument, or the
+   text of the argument, and FROM_TTY is nonzero if this command is
+   being entered directly by the user (i.e. these are just like any
+   other command).  C is the command list element for the command.  */
+
+void
+do_show_command (char *arg, int from_tty, struct cmd_list_element *c)
+{
+  struct ui_out *uiout = current_uiout;
+
+  gdb_assert (c->type == show_cmd);
+  {
       struct cleanup *old_chain;
       struct ui_file *stb;
 
@@ -387,12 +472,9 @@ do_setshow_command (char *arg, int from_tty, struct cmd_list_element *c)
 	    deprecated_show_value_hack (gdb_stdout, from_tty, c, value);
 	}
       do_cleanups (old_chain);
-    }
-  else
-    error (_("gdb internal error: bad cmd_type in do_setshow_command"));
+
   c->func (c, NULL, from_tty);
-  if (c->type == set_cmd && deprecated_set_hook)
-    deprecated_set_hook (c);
+    }
 }
 
 /* Show all the settings in a list of show commands.  */
@@ -431,7 +513,7 @@ cmd_show_list (struct cmd_list_element *list, int from_tty, char *prefix)
 	      ui_out_field_string (uiout, "name", list->name);
 	      ui_out_text (uiout, ":  ");
 	      if (list->type == show_cmd)
-		do_setshow_command ((char *) NULL, from_tty, list);
+		do_show_command ((char *) NULL, from_tty, list);
 	      else
 		cmd_func (list, NULL, from_tty);
 	      /* Close the tuple.  */
diff --git a/gdb/cli/cli-setshow.h b/gdb/cli/cli-setshow.h
index cb8d2c5..8f43e53 100644
--- a/gdb/cli/cli-setshow.h
+++ b/gdb/cli/cli-setshow.h
@@ -21,12 +21,10 @@ struct cmd_list_element;
 
 /* Exported to cli/cli-cmds.c and gdb/top.c */
 
-/* Do a "set" or "show" command.  ARG is NULL if no argument, or the
-   text of the argument, and FROM_TTY is nonzero if this command is
-   being entered directly by the user (i.e. these are just like any
-   other command).  C is the command list element for the command.  */
-extern void do_setshow_command (char *arg, int from_tty,
-				struct cmd_list_element *c);
+extern int do_set_command (char *arg, int from_tty,
+			   struct cmd_list_element *c);
+extern void do_show_command (char *arg, int from_tty,
+			     struct cmd_list_element *c);
 
 /* Exported to cli/cli-cmds.c and gdb/top.c, language.c and valprint.c */
 
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index 14d4ac3..4c44a80 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -234,6 +234,14 @@ the current top-level prompt.
 Variable gdb_datadir has been set.  The value may not necessarily change.
 @end deftypefun
 
+@deftypefun void command_option_changed (const char *@var{option}, const char *@var{value})
+The option of some @code{set} commands in console are changed.  This
+method is called after a command @code{set @var{option} @var{value}}.
+@var{option} is the option of @code{set} command, and @var{value}
+is the value of changed option.
+
+@end deftypefun
+
 @deftypefun void test_notification (int @var{somearg})
 This observer is used for internal testing.  Do not use.  
 See testsuite/gdb.gdb/observer.exp.
diff --git a/gdb/remote.c b/gdb/remote.c
index fa514dc..87b8921 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -11270,7 +11270,7 @@ show_remote_cmd (char *args, int from_tty)
 	ui_out_field_string (uiout, "name", list->name);
 	ui_out_text (uiout, ":  ");
 	if (list->type == show_cmd)
-	  do_setshow_command ((char *) NULL, from_tty, list);
+	  do_show_command ((char *) NULL, from_tty, list);
 	else
 	  cmd_func (list, NULL, from_tty);
 	/* Close the tuple.  */
diff --git a/gdb/top.c b/gdb/top.c
index 061ad48..46fa9c3 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -412,7 +412,7 @@ execute_command (char *p, int from_tty)
 {
   struct cleanup *cleanup_if_error, *cleanup;
   struct cmd_list_element *c;
-  char *line;
+  char *line, *orig;
 
   cleanup_if_error = make_bpstat_clear_actions_cleanup ();
   cleanup = prepare_execute_command ();
@@ -468,14 +468,30 @@ execute_command (char *p, int from_tty)
       /* If this command has been pre-hooked, run the hook first.  */
       execute_cmd_pre_hook (c);
 
+      orig = line;
       if (c->flags & DEPRECATED_WARN_USER)
 	deprecated_cmd_warning (&line);
 
       /* c->user_commands would be NULL in the case of a python command.  */
       if (c->class == class_user && c->user_commands)
 	execute_user_command (c, arg);
-      else if (c->type == set_cmd || c->type == show_cmd)
-	do_setshow_command (arg, from_tty, c);
+      else if (c->type == set_cmd)
+	{
+	  if (do_set_command (arg, from_tty, c) && c->notify_observer_p)
+	    {
+	      /* Skip 'set ' */
+	      int len = arg - orig - 4;
+	      char *option = xmalloc (len);
+
+	      memcpy (option, orig + 4, len - 1);
+	      option[len - 1] = 0;
+
+	      observer_notify_command_option_changed (option, arg);
+	      xfree (option);
+	    }
+	}
+      else if (c->type == show_cmd)
+	do_show_command (arg, from_tty, c);
       else if (!cmd_func_p (c))
 	error (_("That is not a command, just a help topic."));
       else if (deprecated_call_command_hook)
-- 
1.7.7.6