[RFA 4/8] Make strip_bg_char return a unique_xmalloc_ptr

[Tom Tromey <tom at tromey dot com>]

This changes strip_bg_char to return a unique_xmalloc_ptr and removes
several cleanups.

gdb/ChangeLog
2017-10-13  Tom Tromey  <tom@tromey.com>

	* infcmd.c (strip_bg_char): Return gdb::unique_xmalloc_ptr.
	(run_command_1, continue_command, step_1, jump_command)
	(signal_command, until_command, advance_command, finish_command)
	(attach_command): Update.
---
 gdb/ChangeLog |  7 +++++
 gdb/infcmd.c  | 84 ++++++++++++++++++-----------------------------------------
 2 files changed, 32 insertions(+), 59 deletions(-)

diff --git a/gdb/infcmd.c b/gdb/infcmd.c
index 669631bdb4..125051fa63 100644
--- a/gdb/infcmd.c
+++ b/gdb/infcmd.c
@@ -421,7 +421,7 @@ construct_inferior_arguments (int argc, char **argv)
    NULL is returned.  *BG_CHAR_P is an output boolean that indicates
    whether the '&' character was found.  */
 
-static char *
+static gdb::unique_xmalloc_ptr<char>
 strip_bg_char (const char *args, int *bg_char_p)
 {
   const char *p;
@@ -441,13 +441,14 @@ strip_bg_char (const char *args, int *bg_char_p)
 
       *bg_char_p = 1;
       if (p != args)
-	return savestring (args, p - args);
+	return gdb::unique_xmalloc_ptr<char>
+	  (savestring (args, p - args));
       else
-	return NULL;
+	return gdb::unique_xmalloc_ptr<char> (nullptr);
     }
 
   *bg_char_p = 0;
-  return xstrdup (args);
+  return gdb::unique_xmalloc_ptr<char> (xstrdup (args));
 }
 
 /* Common actions to take after creating any sort of inferior, by any
@@ -592,7 +593,6 @@ run_command_1 (char *args, int from_tty, enum run_how run_how)
   struct ui_out *uiout = current_uiout;
   struct target_ops *run_target;
   int async_exec;
-  struct cleanup *args_chain;
   CORE_ADDR pc;
 
   dont_repeat ();
@@ -616,8 +616,8 @@ run_command_1 (char *args, int from_tty, enum run_how run_how)
   reopen_exec_file ();
   reread_symbols ();
 
-  args = strip_bg_char (args, &async_exec);
-  args_chain = make_cleanup (xfree, args);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (args, &async_exec);
+  args = stripped.get ();
 
   /* Do validation and preparation before possibly changing anything
      in the inferior.  */
@@ -663,9 +663,6 @@ run_command_1 (char *args, int from_tty, enum run_how run_how)
       uiout->flush ();
     }
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   /* We call get_inferior_args() because we might need to compute
      the value now.  */
   run_target->to_create_inferior (run_target, exec_file,
@@ -850,13 +847,12 @@ continue_command (char *args, int from_tty)
 {
   int async_exec;
   int all_threads = 0;
-  struct cleanup *args_chain;
 
   ERROR_NO_INFERIOR;
 
   /* Find out whether we must run in the background.  */
-  args = strip_bg_char (args, &async_exec);
-  args_chain = make_cleanup (xfree, args);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (args, &async_exec);
+  args = stripped.get ();
 
   if (args != NULL)
     {
@@ -918,9 +914,6 @@ continue_command (char *args, int from_tty)
 	}
     }
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   ERROR_NO_INFERIOR;
   ensure_not_tfind_mode ();
 
@@ -1065,7 +1058,6 @@ step_1 (int skip_subroutines, int single_inst, char *count_string)
 {
   int count;
   int async_exec;
-  struct cleanup *args_chain;
   struct thread_info *thr;
   struct step_command_fsm *step_sm;
 
@@ -1074,16 +1066,14 @@ step_1 (int skip_subroutines, int single_inst, char *count_string)
   ensure_valid_thread ();
   ensure_not_running ();
 
-  count_string = strip_bg_char (count_string, &async_exec);
-  args_chain = make_cleanup (xfree, count_string);
+  gdb::unique_xmalloc_ptr<char> stripped =
+    strip_bg_char (count_string, &async_exec);
+  count_string = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
   count = count_string ? parse_and_eval_long (count_string) : 1;
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   clear_proceed_status (1);
 
   /* Setup the execution command state machine to handle all the COUNT
@@ -1259,7 +1249,6 @@ jump_command (char *arg, int from_tty)
   struct symbol *fn;
   struct symbol *sfn;
   int async_exec;
-  struct cleanup *args_chain;
 
   ERROR_NO_INFERIOR;
   ensure_not_tfind_mode ();
@@ -1267,8 +1256,8 @@ jump_command (char *arg, int from_tty)
   ensure_not_running ();
 
   /* Find out whether we must run in the background.  */
-  arg = strip_bg_char (arg, &async_exec);
-  args_chain = make_cleanup (xfree, arg);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (arg, &async_exec);
+  arg = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
@@ -1280,9 +1269,6 @@ jump_command (char *arg, int from_tty)
   if (sals.size () != 1)
     error (_("Unreasonable jump request"));
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   symtab_and_line &sal = sals[0];
 
   if (sal.symtab == 0 && sal.pc == 0)
@@ -1341,7 +1327,6 @@ signal_command (char *signum_exp, int from_tty)
 {
   enum gdb_signal oursig;
   int async_exec;
-  struct cleanup *args_chain;
 
   dont_repeat ();		/* Too dangerous.  */
   ERROR_NO_INFERIOR;
@@ -1350,8 +1335,9 @@ signal_command (char *signum_exp, int from_tty)
   ensure_not_running ();
 
   /* Find out whether we must run in the background.  */
-  signum_exp = strip_bg_char (signum_exp, &async_exec);
-  args_chain = make_cleanup (xfree, signum_exp);
+  gdb::unique_xmalloc_ptr<char> stripped
+    = strip_bg_char (signum_exp, &async_exec);
+  signum_exp = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
@@ -1374,8 +1360,6 @@ signal_command (char *signum_exp, int from_tty)
 	oursig = gdb_signal_from_command (num);
     }
 
-  do_cleanups (args_chain);
-
   /* Look for threads other than the current that this command ends up
      resuming too (due to schedlock off), and warn if they'll get a
      signal delivered.  "signal 0" is used to suppress a previous
@@ -1620,7 +1604,6 @@ static void
 until_command (char *arg, int from_tty)
 {
   int async_exec;
-  struct cleanup *args_chain;
 
   ERROR_NO_INFERIOR;
   ensure_not_tfind_mode ();
@@ -1628,8 +1611,8 @@ until_command (char *arg, int from_tty)
   ensure_not_running ();
 
   /* Find out whether we must run in the background.  */
-  arg = strip_bg_char (arg, &async_exec);
-  args_chain = make_cleanup (xfree, arg);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (arg, &async_exec);
+  arg = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
@@ -1637,16 +1620,12 @@ until_command (char *arg, int from_tty)
     until_break_command (arg, from_tty, 0);
   else
     until_next_command (from_tty);
-
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
 }
 
 static void
 advance_command (char *arg, int from_tty)
 {
   int async_exec;
-  struct cleanup *args_chain;
 
   ERROR_NO_INFERIOR;
   ensure_not_tfind_mode ();
@@ -1657,15 +1636,12 @@ advance_command (char *arg, int from_tty)
     error_no_arg (_("a location"));
 
   /* Find out whether we must run in the background.  */
-  arg = strip_bg_char (arg, &async_exec);
-  args_chain = make_cleanup (xfree, arg);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (arg, &async_exec);
+  arg = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
   until_break_command (arg, from_tty, 1);
-
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
 }
 
 /* Return the value of the result of a function at the end of a 'finish'
@@ -2031,7 +2007,6 @@ finish_command (char *arg, int from_tty)
 {
   struct frame_info *frame;
   int async_exec;
-  struct cleanup *args_chain;
   struct finish_command_fsm *sm;
   struct thread_info *tp;
 
@@ -2041,17 +2016,14 @@ finish_command (char *arg, int from_tty)
   ensure_not_running ();
 
   /* Find out whether we must run in the background.  */
-  arg = strip_bg_char (arg, &async_exec);
-  args_chain = make_cleanup (xfree, arg);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (arg, &async_exec);
+  arg = stripped.get ();
 
   prepare_execution_command (&current_target, async_exec);
 
   if (arg)
     error (_("The \"finish\" command does not take any arguments."));
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   frame = get_prev_frame (get_selected_frame (_("No selected frame.")));
   if (frame == 0)
     error (_("\"finish\" not meaningful in the outermost frame."));
@@ -2846,7 +2818,6 @@ void
 attach_command (char *args, int from_tty)
 {
   int async_exec;
-  struct cleanup *args_chain;
   struct target_ops *attach_target;
   struct inferior *inferior = current_inferior ();
   enum attach_post_wait_mode mode;
@@ -2869,8 +2840,8 @@ attach_command (char *args, int from_tty)
      this function should probably be moved into target_pre_inferior.  */
   target_pre_inferior (from_tty);
 
-  args = strip_bg_char (args, &async_exec);
-  args_chain = make_cleanup (xfree, args);
+  gdb::unique_xmalloc_ptr<char> stripped = strip_bg_char (args, &async_exec);
+  args = stripped.get ();
 
   attach_target = find_attach_target ();
 
@@ -2948,17 +2919,12 @@ attach_command (char *args, int from_tty)
       a->mode = mode;
       add_inferior_continuation (attach_command_continuation, a,
 				 attach_command_continuation_free_args);
-      /* Done with ARGS.  */
-      do_cleanups (args_chain);
 
       if (!target_is_async_p ())
 	mark_infrun_async_event_handler ();
       return;
     }
 
-  /* Done with ARGS.  */
-  do_cleanups (args_chain);
-
   attach_post_wait (args, from_tty, mode);
 }
 
-- 
2.13.6