gdb: add cmd_list_element::is_prefix

Same idea as the previous patch, but for prefix instead of alias.

gdb/ChangeLog:

	* cli/cli-decode.h (cmd_list_element) <is_prefix>: New, use it.

Change-Id: I76a9d2e82fc8d7429904424674d99ce6f9880e2b

11 files changed, 37 insertions, 31 deletions

diff --git a/gdb/auto-load.c b/gdb/auto-load.c
index 7745aa6..9cd70f1 100644
--- a/gdb/auto-load.c
+++ b/gdb/auto-load.c
@@ -1465,7 +1465,7 @@ info_auto_load_cmd (const char *args, int from_tty)
     {
       ui_out_emit_tuple option_emitter (uiout, "option");
 
-      gdb_assert (!list->subcommands);
+      gdb_assert (!list->is_prefix ());
       gdb_assert (list->type == not_set_cmd);
 
       uiout->field_string ("name", list->name);
diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index c29e597..0bf418e 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -1625,7 +1625,7 @@ show_user (const char *args, int from_tty)
     {
       for (c = cmdlist; c; c = c->next)
 	{
-	  if (cli_user_command_p (c) || c->subcommands != NULL)
+	  if (cli_user_command_p (c) || c->is_prefix ())
 	    show_user_1 (c, "", c->name, gdb_stdout);
 	}
     }
@@ -1900,7 +1900,7 @@ alias_command (const char *args, int from_tty)
       /* We've already tried to look up COMMAND.  */
       gdb_assert (c_command != NULL
 		  && c_command != (struct cmd_list_element *) -1);
-      gdb_assert (c_command->subcommands != NULL);
+      gdb_assert (c_command->is_prefix ());
       c_alias = lookup_cmd_1 (& alias_prefix, cmdlist, NULL, NULL, 1);
       if (c_alias != c_command)
 	error (_("ALIAS and COMMAND prefixes do not match."));
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 29b4ed2..785e726a 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -69,8 +69,9 @@ lookup_cmd_with_subcommands (cmd_list_element **subcommands,
     {
       struct cmd_list_element *q;
 
-      if (p->subcommands == NULL)
+      if (!p->is_prefix ())
 	continue;
+
       else if (p->subcommands == subcommands)
 	{
 	  /* If we found an alias, we must return the aliased
@@ -163,7 +164,7 @@ set_cmd_completer_handle_brkchars (struct cmd_list_element *cmd,
 std::string
 cmd_list_element::prefixname () const
 {
-  if (this->subcommands == nullptr)
+  if (!this->is_prefix ())
     /* Not a prefix command.  */
     return "";
 
@@ -369,7 +370,7 @@ update_prefix_field_of_prefixed_commands (struct cmd_list_element *c)
 	 'auto-load' command was not yet reachable by
 	    lookup_cmd_for_subcommands (list, cmdlist)
 	    that searches from the top level 'cmdlist'.  */
-      if (p->subcommands != nullptr)
+      if (p->is_prefix ())
 	update_prefix_field_of_prefixed_commands (p);
     }
 }
@@ -1184,7 +1185,7 @@ apropos_cmd (struct ui_file *stream,
 	    print_doc_of_command (c, prefix, verbose, regex, stream);
 	}
       /* Check if this command has subcommands.  */
-      if (c->subcommands != NULL)
+      if (c->is_prefix ())
 	{
 	  /* Recursively call ourselves on the subcommand list,
 	     passing the right prefix in.  */
@@ -1249,12 +1250,13 @@ help_cmd (const char *command, struct ui_file *stream)
   fputs_filtered (c->doc, stream);
   fputs_filtered ("\n", stream);
 
-  if (c->subcommands == 0 && c->func != NULL)
+  if (!c->is_prefix () && c->func != NULL)
     return;
+
   fprintf_filtered (stream, "\n");
 
   /* If this is a prefix command, print it's subcommands.  */
-  if (c->subcommands)
+  if (c->is_prefix ())
     help_list (*c->subcommands, c->prefixname ().c_str (),
 	       all_commands, stream);
 
@@ -1446,7 +1448,7 @@ print_help_for_command (struct cmd_list_element *c,
   fput_aliases_definition_styled (c, stream);
 
   if (recurse
-      && c->subcommands != 0
+      && c->is_prefix ()
       && c->abbrev_flag == 0)
     /* Subcommands of a prefix command typically have 'all_commands'
        as class.  If we pass CLASS to recursive invocation,
@@ -1516,7 +1518,7 @@ help_cmd_list (struct cmd_list_element *list, enum command_class theclass,
 
       if (recurse
 	  && (theclass == class_user || theclass == class_alias)
-	  && c->subcommands != NULL)
+	  && c->is_prefix ())
 	{
 	  /* User-defined commands or aliases may be subcommands.  */
 	  help_cmd_list (*c->subcommands, theclass, recurse, stream);
@@ -1694,7 +1696,7 @@ lookup_cmd_1 (const char **text, struct cmd_list_element *clist,
     }
   /* If we found a prefix command, keep looking.  */
 
-  if (found->subcommands)
+  if (found->is_prefix ())
     {
       c = lookup_cmd_1 (text, *found->subcommands, result_list, default_args,
 			ignore_help_classes, lookup_for_completion_p);
@@ -1865,7 +1867,7 @@ lookup_cmd (const char **line, struct cmd_list_element *list,
       while (**line == ' ' || **line == '\t')
 	(*line)++;
 
-      if (c->subcommands && **line && !c->allow_unknown)
+      if (c->is_prefix () && **line && !c->allow_unknown)
 	undef_cmd_error (c->prefixname ().c_str (), *line);
 
       /* Seems to be what he wants.  Return it.  */
@@ -2056,7 +2058,7 @@ lookup_cmd_composition_1 (const char *text,
       text += len;
       text = skip_spaces (text);
 
-      if ((*cmd)->subcommands != nullptr && *text != '\0')
+      if ((*cmd)->is_prefix () && *text != '\0')
 	{
 	  cur_list = *(*cmd)->subcommands;
 	  *prefix_cmd = *cmd;
@@ -2123,7 +2125,7 @@ complete_on_cmdlist (struct cmd_list_element *list,
 	if (!strncmp (ptr->name, text, textlen)
 	    && !ptr->abbrev_flag
 	    && (!ignore_help_classes || ptr->func
-		|| ptr->subcommands))
+		|| ptr->is_prefix ()))
 	  {
 	    if (pass == 0)
 	      {
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index 8caf602..6204ed7 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -83,6 +83,10 @@ struct cmd_list_element
   bool is_alias () const
   { return this->alias_target != nullptr; }
 
+  /* Return true if this command is a prefix command.  */
+  bool is_prefix () const
+  { return this->subcommands != nullptr; }
+
   /* Points to next command in this list.  */
   struct cmd_list_element *next = nullptr;
 
diff --git a/gdb/cli/cli-script.c b/gdb/cli/cli-script.c
index 5ddfab9..ff93523 100644
--- a/gdb/cli/cli-script.c
+++ b/gdb/cli/cli-script.c
@@ -1350,7 +1350,7 @@ validate_comname (const char **comname)
       const char *tem = prefix.c_str ();
 
       c = lookup_cmd (&tem, cmdlist, "", NULL, 0, 1);
-      if (c->subcommands == NULL)
+      if (!c->is_prefix ())
 	error (_("\"%s\" is not a prefix command."), prefix.c_str ());
 
       list = c->subcommands;
@@ -1414,7 +1414,7 @@ do_define_command (const char *comname, int from_tty,
 	  /* if C is a prefix command that was previously defined,
 	     tell the user its subcommands will be kept, and ask
 	     if ok to redefine the command.  */
-	  if (c->subcommands != nullptr)
+	  if (c->is_prefix ())
 	    q = (c->user_commands.get () == nullptr
 		 || query (_("Keeping subcommands of prefix command \"%s\".\n"
 			     "Redefine command \"%s\"? "), c->name, c->name));
@@ -1595,7 +1595,7 @@ define_prefix_command (const char *comname, int from_tty)
   if (c != nullptr && c->theclass != class_user)
     error (_("Command \"%s\" is built-in."), comfull);
 
-  if (c != nullptr && c->subcommands != nullptr)
+  if (c != nullptr && c->is_prefix ())
     {
       /* c is already a user defined prefix command.  */
       return;
@@ -1665,7 +1665,7 @@ show_user_1 (struct cmd_list_element *c, const char *prefix, const char *name,
       struct command_line *cmdlines = c->user_commands.get ();
 
       fprintf_filtered (stream, "User %scommand \"",
-			c->subcommands == NULL ? "" : "prefix ");
+			c->is_prefix () ? "prefix" : "");
       fprintf_styled (stream, title_style.style (), "%s%s",
 		      prefix, name);
       fprintf_filtered (stream, "\":\n");
@@ -1676,12 +1676,12 @@ show_user_1 (struct cmd_list_element *c, const char *prefix, const char *name,
 	}
     }
 
-  if (c->subcommands != NULL)
+  if (c->is_prefix ())
     {
       const std::string prefixname = c->prefixname ();
 
       for (c = *c->subcommands; c != NULL; c = c->next)
-	if (c->theclass == class_user || c->subcommands != NULL)
+	if (c->theclass == class_user || c->is_prefix ())
 	  show_user_1 (c, prefixname.c_str (), c->name, gdb_stdout);
     }
 
diff --git a/gdb/cli/cli-setshow.c b/gdb/cli/cli-setshow.c
index 7e93a70..82008ca 100644
--- a/gdb/cli/cli-setshow.c
+++ b/gdb/cli/cli-setshow.c
@@ -740,7 +740,7 @@ cmd_show_list (struct cmd_list_element *list, int from_tty)
 
       /* If we find a prefix, run its list, prefixing our output by its
 	 prefix (with "show " skipped).  */
-      if (list->subcommands && !list->is_alias ())
+      if (list->is_prefix () && !list->is_alias ())
 	{
 	  ui_out_emit_tuple optionlist_emitter (uiout, "optionlist");
 	  std::string prefixname = list->prefixname ();
@@ -758,7 +758,7 @@ cmd_show_list (struct cmd_list_element *list, int from_tty)
 	    {
 	      /* If we find a prefix, output it (with "show " skipped).  */
 	      std::string prefixname = list->prefix->prefixname ();
-	      prefixname = (list->prefix->subcommands == nullptr ? ""
+	      prefixname = (!list->prefix->is_prefix () ? ""
 			    : strstr (prefixname.c_str (), "show ") + 5);
 	      uiout->text (prefixname.c_str ());
 	    }
diff --git a/gdb/completer.c b/gdb/completer.c
index 6d39435..6ad788b 100644
--- a/gdb/completer.c
+++ b/gdb/completer.c
@@ -1456,7 +1456,7 @@ complete_line_internal_1 (completion_tracker &tracker,
 	    {
 	      /* The command is followed by whitespace; we need to
 		 complete on whatever comes after command.  */
-	      if (c->subcommands)
+	      if (c->is_prefix ())
 		{
 		  /* It is a prefix command; what comes after it is
 		     a subcommand (e.g. "info ").  */
@@ -1524,7 +1524,7 @@ complete_line_internal_1 (completion_tracker &tracker,
 	{
 	  /* There is non-whitespace beyond the command.  */
 
-	  if (c->subcommands && !c->allow_unknown)
+	  if (c->is_prefix () && !c->allow_unknown)
 	    {
 	      /* It is an unrecognized subcommand of a prefix command,
 		 e.g. "info adsfkdj".  */
diff --git a/gdb/guile/scm-cmd.c b/gdb/guile/scm-cmd.c
index fc7dc2b..39c915e 100644
--- a/gdb/guile/scm-cmd.c
+++ b/gdb/guile/scm-cmd.c
@@ -524,7 +524,7 @@ gdbscm_parse_command_name (const char *name,
 				 gdbscm_scm_from_c_string (name), msg);
     }
 
-  if (elt->subcommands)
+  if (elt->is_prefix ())
     {
       xfree (prefix_text);
       *base_list = elt->subcommands;
diff --git a/gdb/python/py-cmd.c b/gdb/python/py-cmd.c
index c2c0df5..4f01fc0 100644
--- a/gdb/python/py-cmd.c
+++ b/gdb/python/py-cmd.c
@@ -111,7 +111,7 @@ cmdpy_function (struct cmd_list_element *command,
     error (_("Invalid invocation of Python command object."));
   if (! PyObject_HasAttr ((PyObject *) obj, invoke_cst))
     {
-      if (obj->command->subcommands != nullptr)
+      if (obj->command->is_prefix ())
 	{
 	  /* A prefix command does not need an invoke method.  */
 	  return;
@@ -393,7 +393,7 @@ gdbpy_parse_command_name (const char *name,
       return NULL;
     }
 
-  if (elt->subcommands)
+  if (elt->is_prefix ())
     {
       *base_list = elt->subcommands;
       return result;
diff --git a/gdb/top.c b/gdb/top.c
index a391e93..a1a932a 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -647,7 +647,7 @@ execute_command (const char *p, int from_tty)
       if (c->theclass == class_user && c->user_commands)
 	execute_user_command (c, arg);
       else if (c->theclass == class_user
-	       && c->subcommands && !c->allow_unknown)
+	       && c->is_prefix () && !c->allow_unknown)
 	/* If this is a user defined prefix that does not allow unknown
 	   (in other words, C is a prefix command and not a command
 	   that can be followed by its args), report the list of
diff --git a/gdb/unittests/command-def-selftests.c b/gdb/unittests/command-def-selftests.c
index 4a6b678..e99eb9b 100644
--- a/gdb/unittests/command-def-selftests.c
+++ b/gdb/unittests/command-def-selftests.c
@@ -83,7 +83,7 @@ check_doc (struct cmd_list_element *commandlist, const char *prefix)
       /* Check if this command has subcommands and is not an
 	 abbreviation.  We skip checking subcommands of abbreviations
 	 in order to avoid duplicates in the output.  */
-      if (c->subcommands != NULL && !c->abbrev_flag)
+      if (c->is_prefix () && !c->abbrev_flag)
 	{
 	  /* Recursively call ourselves on the subcommand list,
 	     passing the right prefix in.  */
@@ -155,7 +155,7 @@ traverse_command_structure (struct cmd_list_element **list,
     {
       /* If this command has subcommands and is not an alias,
 	 traverse the subcommands.  */
-      if (c->subcommands != NULL && !c->is_alias ())
+      if (c->is_prefix () && !c->is_alias ())
 	{
 	  /* Recursively call ourselves on the subcommand list,
 	     passing the right prefix in.  */