Remove more calls to xfree from Python

This changes the Python code to remove some more calls to xfree, in
favor of self-managing data structures.

Tested on x86-64 Fedora 28.

gdb/ChangeLog
2018-12-27  Tom Tromey  <tom@tromey.com>

	* python/python.c (python_interactive_command): Use std::string.
	(gdbpy_parameter): Likewise.
	* python/py-utils.c (unicode_to_encoded_string): Update comment.
	* python/py-symtab.c (salpy_str): Use PyString_FromFormat.
	* python/py-record-btrace.c (recpy_bt_insn_data): Use
	byte_vector.
	* python/py-objfile.c (objfpy_get_build_id): Use
	unique_xmalloc_ptr.
	* python/py-inferior.c (infpy_read_memory): Use
	unique_xmalloc_ptr.
	* python/py-cmd.c (gdbpy_parse_command_name): Use std::string.

1 files changed, 5 insertions, 15 deletions

diff --git a/gdb/python/python.c b/gdb/python/python.c
index d6453e7..f790d48 100644
--- a/gdb/python/python.c
+++ b/gdb/python/python.c
@@ -296,14 +296,8 @@ python_interactive_command (const char *arg, int from_tty)
 
   if (arg && *arg)
     {
-      int len = strlen (arg);
-      char *script = (char *) xmalloc (len + 2);
-
-      strcpy (script, arg);
-      script[len] = '\n';
-      script[len + 1] = '\0';
-      err = eval_python_command (script);
-      xfree (script);
+      std::string script = std::string (arg) + "\n";
+      err = eval_python_command (script.c_str ());
     }
   else
     {
@@ -495,29 +489,25 @@ gdbpy_parameter_value (enum var_types type, void *var)
 static PyObject *
 gdbpy_parameter (PyObject *self, PyObject *args)
 {
-  struct gdb_exception except = exception_none;
   struct cmd_list_element *alias, *prefix, *cmd;
   const char *arg;
-  char *newarg;
   int found = -1;
 
   if (! PyArg_ParseTuple (args, "s", &arg))
     return NULL;
 
-  newarg = concat ("show ", arg, (char *) NULL);
+  std::string newarg = std::string ("show ") + arg;
 
   TRY
     {
-      found = lookup_cmd_composition (newarg, &alias, &prefix, &cmd);
+      found = lookup_cmd_composition (newarg.c_str (), &alias, &prefix, &cmd);
     }
   CATCH (ex, RETURN_MASK_ALL)
     {
-      except = ex;
+      GDB_PY_HANDLE_EXCEPTION (ex);
     }
   END_CATCH
 
-  xfree (newarg);
-  GDB_PY_HANDLE_EXCEPTION (except);
   if (!found)
     return PyErr_Format (PyExc_RuntimeError,
 			 _("Could not find parameter `%s'."), arg);