Use accessor for mi_parse::args

This changes mi_parse::args to be a private member, retrieved via
accessor.  It also changes this member to be a std::string.  This
makes it simpler for a subsequent patch to implement different
behavior for argument parsing.

gdb/mi/mi-cmds.c

@@ -49,11 +49,11 @@ struct mi_command_mi : public mi_command
      with arguments contained within PARSE.  */
   void invoke (struct mi_parse *parse) const override
   {
-    mi_parse_argv (parse->args, parse);
+    mi_parse_argv (parse->args (), parse);
 
     if (parse->argv == nullptr)
       error (_("Problem parsing arguments: %s %s"), parse->command,
-	     parse->args);
+	     parse->args ());
 
     this->m_argv_function (parse->command, parse->argv, parse->argc);
   }
@@ -87,7 +87,7 @@ struct mi_command_cli : public mi_command
      is passed through to the CLI function as its argument string.  */
   void invoke (struct mi_parse *parse) const override
   {
-    const char *args = m_args_p ? parse->args : nullptr;
+    const char *args = m_args_p ? parse->args () : nullptr;
     mi_execute_cli_command (m_cli_name, m_args_p, args);
   }
 

gdb/mi/mi-main.c

@@ -1813,7 +1813,7 @@ captured_mi_execute_command (struct ui_out *uiout, struct mi_parse *context)
       if (mi_debug_p)
 	gdb_printf (gdb_stdlog,
 		    " token=`%s' command=`%s' args=`%s'\n",
-		    context->token, context->command, context->args);
+		    context->token, context->command, context->args ());
 
       mi_cmd_execute (context);
 

gdb/mi/mi-parse.c

@@ -212,7 +212,6 @@ mi_parse::~mi_parse ()
 {
   xfree (command);
   xfree (token);
-  xfree (args);
   freeargv (argv);
 }
 
@@ -346,7 +345,7 @@ mi_parse (const char *cmd, char **token)
     }
 
   /* Save the rest of the arguments for the command.  */
-  parse->args = xstrdup (chp);
+  parse->set_args (chp);
 
   /* Fully parsed, flag as an MI command.  */
   parse->op = MI_COMMAND;

gdb/mi/mi-parse.h

@@ -46,12 +46,19 @@ struct mi_parse
 
     DISABLE_COPY_AND_ASSIGN (mi_parse);
 
+    /* Return the full argument string, as used by commands which are
+       implemented as CLI commands.  */
+    const char *args () const
+    { return m_args.c_str (); }
+
+    void set_args (const char *args)
+    { m_args = args; }
+
     enum mi_command_type op = MI_COMMAND;
     char *command = nullptr;
     char *token = nullptr;
     const struct mi_command *cmd = nullptr;
     struct mi_timestamp *cmd_start = nullptr;
-    char *args = nullptr;
     char **argv = nullptr;
     int argc = 0;
     int all = 0;
@@ -62,6 +69,10 @@ struct mi_parse
     /* The language that should be used to evaluate the MI command.
        Ignored if set to language_unknown.  */
     enum language language = language_unknown;
+
+  private:
+
+    std::string m_args;
   };
 
 /* Attempts to parse CMD returning a ``struct mi_parse''.  If CMD is

gdb/python/py-micmd.c

@@ -355,10 +355,11 @@ mi_command_py::invoke (struct mi_parse *parse) const
 
   pymicmd_debug_printf ("this = %p, name = %s", this, name ());
 
-  mi_parse_argv (parse->args, parse);
+  mi_parse_argv (parse->args (), parse);
 
   if (parse->argv == nullptr)
-    error (_("Problem parsing arguments: %s %s"), parse->command, parse->args);
+    error (_("Problem parsing arguments: %s %s"), parse->command,
+	   parse->args ());
 
 
   gdbpy_enter enter_py;