gdb: rename cfunc to simple_func

After browsing the CLI code for quite a while and trying really hard, I
reached the conclusion that I can't give a meaningful explanation of
what "sfunc" and "cfunc" functions are, in cmd_list_element.  I don't
see a logic at all.  That makes it very difficult to do any kind of
change.  Unless somebody can make sense out of all that, I'd like to try
to retro-fit some logic in the cmd_list_element callback function code
so that we can understand what is going on, do some cleanups and add new
features.

The first change is about "cfunc".  I can't figure out what the "c" in
cfunc means.  It's not const, because there's already "const" in
"cmd_const_cfunc_ftype", and the previous "cmd_cfunc_ftype" had nothing
const..  It's not "cmd" or "command", because there's already "cmd" in
"cmd_const_cfunc_ftype".

The "main" command callback, cmd_list_element::func, has three
parameters, whereas cfunc has two.  It is missing the cmd_list_element
parameter.  So the only reason I see for cfunc to exist is to be a shim
between the three and two parameter versions.  Most commands don't need
to receive the cmd_list_element object, so adding it everywhere would be
long and would just add more unnecessary boilerplate.  So since this is
the "simple" version of the callback, compared to the "full", I suggest
renaming cmd_const_cfunc_ftype into cmd_simple_func_ftype, as well as
everything (like the utility functions) that goes with it.

Change-Id: I4e46cacfd77a66bc1cbf683f6a362072504b7868

3 files changed, 30 insertions, 24 deletions

diff --git a/gdb/cli/cli-cmds.c b/gdb/cli/cli-cmds.c
index 56ae12a..5ff0b77 100644
--- a/gdb/cli/cli-cmds.c
+++ b/gdb/cli/cli-cmds.c
@@ -443,7 +443,7 @@ complete_command (const char *arg, int from_tty)
 int
 is_complete_command (struct cmd_list_element *c)
 {
-  return cmd_cfunc_eq (c, complete_command);
+  return cmd_simple_func_eq (c, complete_command);
 }
 
 static void
diff --git a/gdb/cli/cli-decode.c b/gdb/cli/cli-decode.c
index 633a3ad..3c39e47 100644
--- a/gdb/cli/cli-decode.c
+++ b/gdb/cli/cli-decode.c
@@ -94,22 +94,23 @@ print_help_for_command (struct cmd_list_element *c,
 
 /* Set the callback function for the specified command.  For each both
    the commands callback and func() are set.  The latter set to a
-   bounce function (unless cfunc / sfunc is NULL that is).  */
+   bounce function (unless simple_func / sfunc is NULL that is).  */
 
 static void
-do_const_cfunc (struct cmd_list_element *c, const char *args, int from_tty)
+do_simple_func (struct cmd_list_element *c, const char *args, int from_tty)
 {
-  c->function.const_cfunc (args, from_tty);
+  c->function.simple_func (args, from_tty);
 }
 
 static void
-set_cmd_cfunc (struct cmd_list_element *cmd, cmd_const_cfunc_ftype *cfunc)
+set_cmd_simple_func (struct cmd_list_element *cmd, cmd_simple_func_ftype *simple_func)
 {
-  if (cfunc == NULL)
+  if (simple_func == NULL)
     cmd->func = NULL;
   else
-    cmd->func = do_const_cfunc;
-  cmd->function.const_cfunc = cfunc;
+    cmd->func = do_simple_func;
+
+  cmd->function.simple_func = simple_func;
 }
 
 static void
@@ -129,9 +130,10 @@ set_cmd_sfunc (struct cmd_list_element *cmd, cmd_const_sfunc_ftype *sfunc)
 }
 
 int
-cmd_cfunc_eq (struct cmd_list_element *cmd, cmd_const_cfunc_ftype *cfunc)
+cmd_simple_func_eq (struct cmd_list_element *cmd, cmd_simple_func_ftype *simple_func)
 {
-  return cmd->func == do_const_cfunc && cmd->function.const_cfunc == cfunc;
+  return (cmd->func == do_simple_func
+	  && cmd->function.simple_func == simple_func);
 }
 
 void
@@ -238,17 +240,17 @@ add_cmd (const char *name, enum command_class theclass,
 {
   cmd_list_element *result = do_add_cmd (name, theclass, doc, list);
   result->func = NULL;
-  result->function.const_cfunc = NULL;
+  result->function.simple_func = NULL;
   return result;
 }
 
 struct cmd_list_element *
 add_cmd (const char *name, enum command_class theclass,
-	 cmd_const_cfunc_ftype *fun,
+	 cmd_simple_func_ftype *fun,
 	 const char *doc, struct cmd_list_element **list)
 {
   cmd_list_element *result = do_add_cmd (name, theclass, doc, list);
-  set_cmd_cfunc (result, fun);
+  set_cmd_simple_func (result, fun);
   return result;
 }
 
@@ -256,7 +258,7 @@ add_cmd (const char *name, enum command_class theclass,
 
 struct cmd_list_element *
 add_cmd_suppress_notification (const char *name, enum command_class theclass,
-			       cmd_const_cfunc_ftype *fun, const char *doc,
+			       cmd_simple_func_ftype *fun, const char *doc,
 			       struct cmd_list_element **list,
 			       int *suppress_notification)
 {
@@ -359,7 +361,7 @@ update_prefix_field_of_prefixed_commands (struct cmd_list_element *c)
 
 struct cmd_list_element *
 add_prefix_cmd (const char *name, enum command_class theclass,
-		cmd_const_cfunc_ftype *fun,
+		cmd_simple_func_ftype *fun,
 		const char *doc, struct cmd_list_element **subcommands,
 		int allow_unknown, struct cmd_list_element **list)
 {
@@ -432,7 +434,7 @@ add_show_prefix_cmd (const char *name, enum command_class theclass,
 struct cmd_list_element *
 add_prefix_cmd_suppress_notification
 	       (const char *name, enum command_class theclass,
-		cmd_const_cfunc_ftype *fun,
+		cmd_simple_func_ftype *fun,
 		const char *doc, struct cmd_list_element **subcommands,
 		int allow_unknown, struct cmd_list_element **list,
 		int *suppress_notification)
@@ -448,7 +450,7 @@ add_prefix_cmd_suppress_notification
 
 struct cmd_list_element *
 add_abbrev_prefix_cmd (const char *name, enum command_class theclass,
-		       cmd_const_cfunc_ftype *fun, const char *doc,
+		       cmd_simple_func_ftype *fun, const char *doc,
 		       struct cmd_list_element **subcommands,
 		       int allow_unknown, struct cmd_list_element **list)
 {
@@ -460,7 +462,7 @@ add_abbrev_prefix_cmd (const char *name, enum command_class theclass,
   return c;
 }
 
-/* This is an empty "cfunc".  */
+/* This is an empty "simple func".  */
 void
 not_just_help_class_command (const char *args, int from_tty)
 {
@@ -951,7 +953,7 @@ delete_cmd (const char *name, struct cmd_list_element **list,
 /* Add an element to the list of info subcommands.  */
 
 struct cmd_list_element *
-add_info (const char *name, cmd_const_cfunc_ftype *fun, const char *doc)
+add_info (const char *name, cmd_simple_func_ftype *fun, const char *doc)
 {
   return add_cmd (name, class_info, fun, doc, &infolist);
 }
@@ -968,7 +970,7 @@ add_info_alias (const char *name, cmd_list_element *target, int abbrev_flag)
 
 struct cmd_list_element *
 add_com (const char *name, enum command_class theclass,
-	 cmd_const_cfunc_ftype *fun,
+	 cmd_simple_func_ftype *fun,
 	 const char *doc)
 {
   return add_cmd (name, theclass, fun, doc, &cmdlist);
@@ -990,7 +992,7 @@ add_com_alias (const char *name, cmd_list_element *target,
 
 struct cmd_list_element *
 add_com_suppress_notification (const char *name, enum command_class theclass,
-			       cmd_const_cfunc_ftype *fun, const char *doc,
+			       cmd_simple_func_ftype *fun, const char *doc,
 			       int *suppress_notification)
 {
   return add_cmd_suppress_notification (name, theclass, fun, doc,
@@ -2167,5 +2169,5 @@ int
 cli_user_command_p (struct cmd_list_element *cmd)
 {
   return (cmd->theclass == class_user
-	  && (cmd->func == do_const_cfunc || cmd->func == do_sfunc));
+	  && (cmd->func == do_simple_func || cmd->func == do_sfunc));
 }
diff --git a/gdb/cli/cli-decode.h b/gdb/cli/cli-decode.h
index 241535a..4cbdf7f 100644
--- a/gdb/cli/cli-decode.h
+++ b/gdb/cli/cli-decode.h
@@ -174,8 +174,12 @@ struct cmd_list_element
      to one of the below.  */
   union
     {
-      /* If type is not_set_cmd, call it like this: */
-      cmd_const_cfunc_ftype *const_cfunc;
+      /* Most commands don't need the cmd_list_element parameter passed to FUNC.
+	 They therefore register a command of this type, which doesn't have the
+	 cmd_list_element parameter.  do_simple_func is installed as FUNC, and
+	 acts as a shim between the two.  */
+      cmd_simple_func_ftype *simple_func;
+
       /* If type is set_cmd or show_cmd, first set the variables,
 	 and then call this: */
       cmd_const_sfunc_ftype *sfunc;