Do target_terminal_ours in query & friends instead of in all callers

Any time a caller calls query & friends / prompt_for_continue without
ensuring that gdb owns the terminal for input is a bug.  So do that in
defaulted_query / prompt_for_continue directly instead.

An example of a case where we currently miss calling
target_terminal_ours is internal_error.  Ever since defaulted_query
was made to use gdb_readline_callback, there's no way to answer the
internal error query if the internal error happens while the target is
has the terminal:

  (gdb) c
  Continuing.
  .../src/gdb/linux-nat.c:1676: internal-error: linux_nat_resume: Assertion `dummy_counter < 10' failed.
  A problem internal to GDB has been detected,
  further debugging may prove unreliable.
  Quit this debugging session? (y or n) _

Entering 'y' or 'n' does not work, GDB does not respond.

gdb/ChangeLog:
2016-04-12  Pedro Alves  <palves@redhat.com>

	PR gdb/19828
	* gnu-nat.c (inf_validate_task_sc): Don't call
	target_terminal_ours / target_terminal_inferior around query.
	* i386-tdep.c (i386_record_lea_modrm, i386_process_record): Don't
	call target_terminal_ours / target_terminal_inferior around
	yquery.
	* linux-record.c (record_linux_system_call): Don't call
	target_terminal_ours / target_terminal_inferior around yquery.
	* nto-procfs.c (interrupt_query): Don't call target_terminal_ours
	/ target_terminal_inferior around query.
	* record-full.c (record_full_check_insn_num): Remove
	'set_terminal' parameter.  Don't call target_terminal_ours /
	target_terminal_inferior around query.
	(record_full_message, record_full_registers_change)
	(record_full_xfer_partial): Adjust.
	* remote.c (interrupt_query): Don't call target_terminal_ours /
	target_terminal_inferior around query.
	* utils.c (defaulted_query): Install cleanup to restore target
	terminal.  Put target_terminal_ours_for_output in effect while
	defaulted producing, and target_terminal_ours in in effect while
	handling input.
	(prompt_for_continue): Install cleanup to restore target terminal.
	Put target_terminal_ours in in effect while handling input.

1 files changed, 13 insertions, 3 deletions

diff --git a/gdb/utils.c b/gdb/utils.c
index 760c376..6c2d1d4 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -1274,12 +1274,15 @@ defaulted_query (const char *ctlstr, const char defchar, va_list args)
   if (!confirm || server_command)
     return def_value;
 
+  old_chain = make_cleanup_restore_target_terminal ();
+
   /* If input isn't coming from the user directly, just say what
      question we're asking, and then answer the default automatically.  This
      way, important error messages don't get lost when talking to GDB
      over a pipe.  */
   if (! input_from_terminal_p ())
     {
+      target_terminal_ours_for_output ();
       wrap_here ("");
       vfprintf_filtered (gdb_stdout, ctlstr, args);
 
@@ -1288,15 +1291,18 @@ defaulted_query (const char *ctlstr, const char defchar, va_list args)
 		       y_string, n_string, def_answer);
       gdb_flush (gdb_stdout);
 
+      do_cleanups (old_chain);
       return def_value;
     }
 
   if (deprecated_query_hook)
     {
-      return deprecated_query_hook (ctlstr, args);
-    }
+      int res;
 
-  old_chain = make_cleanup (null_cleanup, NULL);
+      res = deprecated_query_hook (ctlstr, args);
+      do_cleanups (old_chain);
+      return res;
+    }
 
   /* Format the question outside of the loop, to avoid reusing args.  */
   question = xstrvprintf (ctlstr, args);
@@ -1310,6 +1316,9 @@ defaulted_query (const char *ctlstr, const char defchar, va_list args)
   /* Used for calculating time spend waiting for user.  */
   gettimeofday (&prompt_started, NULL);
 
+  /* We'll need to handle input.  */
+  target_terminal_ours ();
+
   while (1)
     {
       char *response, answer;
@@ -1881,6 +1890,7 @@ prompt_for_continue (void)
   reinitialize_more_filter ();
 
   /* We'll need to handle input.  */
+  make_cleanup_restore_target_terminal ();
   target_terminal_ours ();
 
   /* Call gdb_readline_wrapper, not readline, in order to keep an