[RFA,v3,2/4] C++-ify break-catch-throw

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 1540f1c..a3a23b6 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,15 @@ 
 2017-06-04  Tom Tromey  <tom@tromey.com>
 
+	* break-catch-throw.c (struct exception_catchpoint)
+	<exception_rx>: Now a std::string.
+	(~exception_catchpoint): Remove.
+	(print_one_detail_exception_catchpoint): Update.
+	(handle_gnu_v3_exceptions): Change type of except_rx.
+	(extract_exception_regexp): Return a std::string.
+	(catch_exception_command_1): Update.
+
+2017-06-04  Tom Tromey  <tom@tromey.com>
+
 	* break-catch-sig.c (gdb_signal_type): Remove typedef.
 	(struct signal_catchpoint) <signals_to_be_caught>: Now a
 	std::vector.
diff --git a/gdb/break-catch-throw.c b/gdb/break-catch-throw.c
index 0074d06..e71a885 100644
--- a/gdb/break-catch-throw.c
+++ b/gdb/break-catch-throw.c
@@ -76,16 +76,14 @@  static struct breakpoint_ops gnu_v3_exception_catchpoint_ops;
 
 struct exception_catchpoint : public breakpoint
 {
-  ~exception_catchpoint () override;
-
   /* The kind of exception catchpoint.  */
 
   enum exception_event_kind kind;
 
-  /* If non-NULL, an xmalloc'd string holding the source form of the
-     regular expression to match against.  */
+  /* If not empty, a string holding the source form of the regular
+     expression to match against.  */
 
-  char *exception_rx;
+  std::string exception_rx;
 
   /* If non-NULL, a compiled regular expression which is used to
      determine which exceptions to stop on.  */
@@ -140,13 +138,6 @@  classify_exception_breakpoint (struct breakpoint *b)
   return cp->kind;
 }
 
-/* exception_catchpoint destructor.  */
-
-exception_catchpoint::~exception_catchpoint ()
-{
-  xfree (this->exception_rx);
-}
-
 /* Implement the 'check_status' method.  */
 
 static void
@@ -319,10 +310,10 @@  print_one_detail_exception_catchpoint (const struct breakpoint *b,
   const struct exception_catchpoint *cp
     = (const struct exception_catchpoint *) b;
 
-  if (cp->exception_rx != NULL)
+  if (!cp->exception_rx.empty ())
     {
       uiout->text (_("\tmatching: "));
-      uiout->field_string ("regexp", cp->exception_rx);
+      uiout->field_string ("regexp", cp->exception_rx.c_str ());
       uiout->text ("\n");
     }
 }
@@ -371,15 +362,15 @@  print_recreate_exception_catchpoint (struct breakpoint *b,
 }
 
 static void
-handle_gnu_v3_exceptions (int tempflag, char *except_rx,
+handle_gnu_v3_exceptions (int tempflag, std::string &&except_rx,
 			  const char *cond_string,
 			  enum exception_event_kind ex_event, int from_tty)
 {
   std::unique_ptr<compiled_regex> pattern;
 
-  if (except_rx != NULL)
+  if (!except_rx.empty ())
     {
-      pattern.reset (new compiled_regex (except_rx, REG_NOSUB,
+      pattern.reset (new compiled_regex (except_rx.c_str (), REG_NOSUB,
 					 _("invalid type-matching regexp")));
     }
 
@@ -410,7 +401,7 @@  handle_gnu_v3_exceptions (int tempflag, char *except_rx,
    STRING is updated to point to the "if" token, if it exists, or to
    the end of the string.  */
 
-static char *
+static std::string
 extract_exception_regexp (const char **string)
 {
   const char *start;
@@ -435,8 +426,8 @@  extract_exception_regexp (const char **string)
 
   *string = last;
   if (last_space > start)
-    return savestring (start, last_space - start);
-  return NULL;
+    return std::string (start, last_space - start);
+  return std::string ();
 }
 
 /* Deal with "catch catch", "catch throw", and "catch rethrow"
@@ -447,17 +438,14 @@  catch_exception_command_1 (enum exception_event_kind ex_event,
 			   char *arg_entry,
 			   int tempflag, int from_tty)
 {
-  char *except_rx;
   const char *cond_string = NULL;
-  struct cleanup *cleanup;
   const char *arg = arg_entry;
 
   if (!arg)
     arg = "";
   arg = skip_spaces_const (arg);
 
-  except_rx = extract_exception_regexp (&arg);
-  cleanup = make_cleanup (xfree, except_rx);
+  std::string except_rx = extract_exception_regexp (&arg);
 
   cond_string = ep_parse_optional_if_clause (&arg);
 
@@ -469,10 +457,8 @@  catch_exception_command_1 (enum exception_event_kind ex_event,
       && ex_event != EX_EVENT_RETHROW)
     error (_("Unsupported or unknown exception event; cannot catch it"));
 
-  handle_gnu_v3_exceptions (tempflag, except_rx, cond_string,
+  handle_gnu_v3_exceptions (tempflag, std::move (except_rx), cond_string,
 			    ex_event, from_tty);
-
-  discard_cleanups (cleanup);
 }
 
 /* Implementation of "catch catch" command.  */