Use ui_file_as_string in execute_command_to_string

... and then return std::string and adjust all callers.

gdb/ChangeLog:
2016-11-08  Pedro Alves  <palves@redhat.com>

	* gdbcmd.h (execute_command_to_string): Now returns std::string.
	(lookup_struct_elt_type): Adjust to use std::string.
	* top.c (execute_command_to_string): Use ui_file_as_string and
	return std::string.
	* guile/guile.c (gdbscm_execute_gdb_command): Adjust to use
	std::string.
	* python/python.c (execute_gdb_command): Adjust to use
	std::string.

1 files changed, 2 insertions, 3 deletions

diff --git a/gdb/top.c b/gdb/top.c
index c7a9c21634..504a4dede1 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -690,12 +690,11 @@ execute_command (char *p, int from_tty)
    returned string, do not display it to the screen.  BATCH_FLAG will be
    temporarily set to true.  */
 
-char *
+std::string
 execute_command_to_string (char *p, int from_tty)
 {
   struct ui_file *str_file;
   struct cleanup *cleanup;
-  char *retval;
 
   /* GDB_STDOUT should be better already restored during these
      restoration callbacks.  */
@@ -725,7 +724,7 @@ execute_command_to_string (char *p, int from_tty)
 
   execute_command (p, from_tty);
 
-  retval = ui_file_xstrdup (str_file, NULL);
+  std::string retval = ui_file_as_string (str_file);
 
   do_cleanups (cleanup);