Let commands free "name"

This adds a "name_allocated" field to cmd_list_element, so that
commands can own their "name" when necessary.  Then, this changes a
few spots in gdb that currently free the name by hand to instead use
this facility.

gdb/ChangeLog
2019-11-26  Tom Tromey  <tom@tromey.com>

	* python/py-function.c (fnpy_init): Update.
	* value.h (add_internal_function): Adjust declaration.
	* value.c (function_destroyer): Remove.
	(do_add_internal_function): Don't set destroyer or copy name.
	(add_internal_function): Take unique_xmalloc_ptr<char> for name.
	Set name_allocated.
	* python/py-cmd.c (cmdpy_destroyer): Don't free "name".
	(cmdpy_init): Set name_allocated.
	* cli/cli-decode.h (struct cmd_list_element) <name_allocated>: New
	member.
	(~cmd_list_element): Free "name" if needed.

Change-Id: Ie1435cea5bbf4bd92056125f112917c607cbb761

gdb/ChangeLog

@@ -1,3 +1,17 @@
+2019-11-26  Tom Tromey  <tom@tromey.com>
+
+	* python/py-function.c (fnpy_init): Update.
+	* value.h (add_internal_function): Adjust declaration.
+	* value.c (function_destroyer): Remove.
+	(do_add_internal_function): Don't set destroyer or copy name.
+	(add_internal_function): Take unique_xmalloc_ptr<char> for name.
+	Set name_allocated.
+	* python/py-cmd.c (cmdpy_destroyer): Don't free "name".
+	(cmdpy_init): Set name_allocated.
+	* cli/cli-decode.h (struct cmd_list_element) <name_allocated>: New
+	member.
+	(~cmd_list_element): Free "name" if needed.
+
 2019-11-26  Tom Tromey  <tom@tromey.com>
 
 	* value.h (add_internal_function): Add new overload.  Move

gdb/cli/cli-decode.h

@@ -55,6 +55,7 @@ struct cmd_list_element
 	deprecated_warn_user (0),
 	malloced_replacement (0),
 	doc_allocated (0),
+	name_allocated (0),
 	hook_in (0),
 	allow_unknown (0),
 	abbrev_flag (0),
@@ -69,6 +70,8 @@ struct cmd_list_element
     {
       if (doc && doc_allocated)
 	xfree ((char *) doc);
+      if (name_allocated)
+	xfree ((char *) name);
     }
 
     DISABLE_COPY_AND_ASSIGN (cmd_list_element);
@@ -109,6 +112,10 @@ struct cmd_list_element
 
     unsigned int doc_allocated : 1;
 
+    /* Set if the name field should be xfree'd.  */
+
+    unsigned int name_allocated : 1;
+
     /* Flag that specifies if this command is already running its hook.  */
     /* Prevents the possibility of hook recursion.  */
     unsigned int hook_in : 1;

gdb/python/py-cmd.c

@@ -98,8 +98,7 @@ cmdpy_destroyer (struct cmd_list_element *self, void *context)
   gdbpy_ref<cmdpy_object> cmd ((cmdpy_object *) context);
   cmd->command = NULL;
 
-  /* We allocated the name and perhaps the prefix name.  */
-  xfree ((char *) self->name);
+  /* We may have allocated the prefix name.  */
   xfree ((char *) self->prefixname);
 }
 
@@ -562,6 +561,7 @@ cmdpy_init (PyObject *self, PyObject *args, PyObject *kw)
       cmd->func = cmdpy_function;
       cmd->destroyer = cmdpy_destroyer;
       cmd->doc_allocated = 1;
+      cmd->name_allocated = 1;
 
       obj->command = cmd;
       set_cmd_context (cmd, self_ref.release ());

gdb/python/py-function.c

@@ -127,8 +127,8 @@ fnpy_init (PyObject *self, PyObject *args, PyObject *kwds)
   if (! docstring)
     docstring.reset (xstrdup (_("This function is not documented.")));
 
-  add_internal_function (name, std::move (docstring), fnpy_call,
-			 self_ref.release ());
+  add_internal_function (make_unique_xstrdup (name), std::move (docstring),
+			 fnpy_call, self_ref.release ());
   return 0;
 }
 

gdb/value.c

@@ -2421,31 +2421,19 @@ function_command (const char *command, int from_tty)
   /* Do nothing.  */
 }
 
-/* Clean up if an internal function's command is destroyed.  */
-static void
-function_destroyer (struct cmd_list_element *self, void *ignore)
-{
-  xfree ((char *) self->name);
-}
-
 /* Helper function that does the work for add_internal_function.  */
 
 static struct cmd_list_element *
 do_add_internal_function (const char *name, const char *doc,
 			  internal_function_fn handler, void *cookie)
 {
-  struct cmd_list_element *cmd;
   struct internal_function *ifn;
   struct internalvar *var = lookup_internalvar (name);
 
   ifn = create_internal_function (name, handler, cookie);
   set_internalvar_function (var, ifn);
 
-  cmd = add_cmd (xstrdup (name), no_class, function_command, (char *) doc,
-		 &functionlist);
-  cmd->destroyer = function_destroyer;
-
-  return cmd;
+  return add_cmd (name, no_class, function_command, doc, &functionlist);
 }
 
 /* See value.h.  */
@@ -2460,13 +2448,16 @@ add_internal_function (const char *name, const char *doc,
 /* See value.h.  */
 
 void
-add_internal_function (const char *name, gdb::unique_xmalloc_ptr<char> &&doc,
+add_internal_function (gdb::unique_xmalloc_ptr<char> &&name,
+		       gdb::unique_xmalloc_ptr<char> &&doc,
 		       internal_function_fn handler, void *cookie)
 {
   struct cmd_list_element *cmd
-    = do_add_internal_function (name, doc.get (), handler, cookie);
+    = do_add_internal_function (name.get (), doc.get (), handler, cookie);
   doc.release ();
   cmd->doc_allocated = 1;
+  name.release ();
+  cmd->name_allocated = 1;
 }
 
 /* Update VALUE before discarding OBJFILE.  COPIED_TYPES is used to

gdb/value.h

@@ -1177,7 +1177,7 @@ extern void add_internal_function (const char *name, const char *doc,
 
 /* This overload takes an allocated documentation string.  */
 
-extern void add_internal_function (const char *name,
+extern void add_internal_function (gdb::unique_xmalloc_ptr<char> &&name,
 				   gdb::unique_xmalloc_ptr<char> &&doc,
 				   internal_function_fn handler,
 				   void *cookie);