Change type of encoding argument to gdbpy_extract_lazy_string

This changes gdbpy_extract_lazy_string's "encoding" argument to be a
unique_xmalloc_ptr.  I chose this rather than std::string because it
can sometimes be NULL.

2017-01-10  Tom Tromey  <tom@tromey.com>

	* python/py-prettyprint.c (print_string_repr, print_children):
	Update.
	* python/py-lazy-string.c (gdbpy_extract_lazy_string): Change type
	of "encoding".
	* varobj.c (varobj_value_get_print_value): Update.
	* python/python-internal.h (gdbpy_extract_lazy_string): Update.

1 files changed, 4 insertions, 5 deletions

diff --git a/gdb/python/py-lazy-string.c b/gdb/python/py-lazy-string.c
index 14575bf..4af4566 100644
--- a/gdb/python/py-lazy-string.c
+++ b/gdb/python/py-lazy-string.c
@@ -180,14 +180,13 @@ gdbpy_is_lazy_string (PyObject *result)
 }
 
 /* Extract the parameters from the lazy string object STRING.
-   ENCODING will either be set to NULL, or will be allocated with
-   xmalloc, in which case the callers is responsible for freeing
-   it.  */
+   ENCODING may be set to NULL, if no encoding is found.  */
 
 void
 gdbpy_extract_lazy_string (PyObject *string, CORE_ADDR *addr,
 			   struct type **str_type,
-			   long *length, char **encoding)
+			   long *length,
+			   gdb::unique_xmalloc_ptr<char> *encoding)
 {
   lazy_string_object *lazy;
 
@@ -198,7 +197,7 @@ gdbpy_extract_lazy_string (PyObject *string, CORE_ADDR *addr,
   *addr = lazy->address;
   *str_type = lazy->type;
   *length = lazy->length;
-  *encoding = lazy->encoding ? xstrdup (lazy->encoding) : NULL;
+  encoding->reset (lazy->encoding ? xstrdup (lazy->encoding) : NULL);
 }