Remove save_inferior_ptid

This removes save_inferior_ptid, a cleanup function, in favor of
scoped_restore.

This also fixes a possible (it seems unlikely that it could happen in
practice) memory leak -- save_inferior_ptid should have used
make_cleanup_dtor, because it allocated memory.

I tested this on the buildbot.  However, there are two caveats to
this.  First, sometimes it seems I misread the results.  Second, I
think this patch touches some platforms that can't be tested by the
buildbot.  So, extra care seems warranted.

ChangeLog
2017-08-18  Tom Tromey  <tom@tromey.com>
	    Pedro Alves  <palves@redhat.com>

	* spu-multiarch.c (parse_spufs_run): Use scoped_restore.
	* sol-thread.c (sol_thread_resume, sol_thread_wait)
	(sol_thread_xfer_partial, rw_common): Use scoped_restore.
	* procfs.c (procfs_do_thread_registers): Use scoped_restore.
	* proc-service.c (ps_xfer_memory): Use scoped_restore.
	* linux-tdep.c (linux_corefile_thread): Remove a cleanup.
	(linux_get_siginfo_data): Add "thread" argument.  Use
	scoped_restore.
	* linux-nat.c (linux_child_follow_fork)
	(check_stopped_by_watchpoint): Use scoped_restore.
	* infrun.c (displaced_step_prepare_throw, write_memory_ptid)
	(THREAD_STOPPED_BY, handle_signal_stop): Use scoped_restore.
	(restore_inferior_ptid, save_inferior_ptid): Remove.
	* btrace.c (btrace_fetch): Use scoped_restore.
	* bsd-uthread.c (bsd_uthread_fetch_registers)
	(bsd_uthread_store_registers): Use scoped_restore.
	* breakpoint.c (reattach_breakpoints, detach_breakpoints): Use
	scoped_restore.
	* aix-thread.c (aix_thread_resume, aix_thread_wait)
	(aix_thread_xfer_partial): Use scoped_restore.
	* inferior.h (save_inferior_ptid): Remove.

1 files changed, 10 insertions, 13 deletions

diff --git a/gdb/aix-thread.c b/gdb/aix-thread.c
index ced6203..f3434a6 100644
--- a/gdb/aix-thread.c
+++ b/gdb/aix-thread.c
@@ -985,12 +985,11 @@ aix_thread_resume (struct target_ops *ops,
 
   if (!PD_TID (ptid))
     {
-      struct cleanup *cleanup = save_inferior_ptid ();
+      scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
       struct target_ops *beneath = find_target_beneath (ops);
       
       inferior_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
       beneath->to_resume (beneath, ptid, step, sig);
-      do_cleanups (cleanup);
     }
   else
     {
@@ -1022,14 +1021,16 @@ static ptid_t
 aix_thread_wait (struct target_ops *ops,
 		 ptid_t ptid, struct target_waitstatus *status, int options)
 {
-  struct cleanup *cleanup = save_inferior_ptid ();
   struct target_ops *beneath = find_target_beneath (ops);
 
-  pid_to_prc (&ptid);
+  {
+    scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
 
-  inferior_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
-  ptid = beneath->to_wait (beneath, ptid, status, options);
-  do_cleanups (cleanup);
+    pid_to_prc (&ptid);
+
+    inferior_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
+    ptid = beneath->to_wait (beneath, ptid, status, options);
+  }
 
   if (ptid_get_pid (ptid) == -1)
     return pid_to_ptid (-1);
@@ -1684,16 +1685,12 @@ aix_thread_xfer_partial (struct target_ops *ops, enum target_object object,
 			 const gdb_byte *writebuf,
 			 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 {
-  struct cleanup *old_chain = save_inferior_ptid ();
-  enum target_xfer_status xfer;
+  scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
   struct target_ops *beneath = find_target_beneath (ops);
 
   inferior_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
-  xfer = beneath->to_xfer_partial (beneath, object, annex, readbuf,
+  return beneath->to_xfer_partial (beneath, object, annex, readbuf,
 				   writebuf, offset, len, xfered_len);
-
-  do_cleanups (old_chain);
-  return xfer;
 }
 
 /* Clean up after the inferior exits.  */