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, 6 insertions, 21 deletions

diff --git a/gdb/sol-thread.c b/gdb/sol-thread.c
index 02515b2..c4d4b02 100644
--- a/gdb/sol-thread.c
+++ b/gdb/sol-thread.c
@@ -367,10 +367,9 @@ static void
 sol_thread_resume (struct target_ops *ops,
 		   ptid_t ptid, int step, enum gdb_signal signo)
 {
-  struct cleanup *old_chain;
   struct target_ops *beneath = find_target_beneath (ops);
 
-  old_chain = save_inferior_ptid ();
+  scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
 
   inferior_ptid = thread_to_lwp (inferior_ptid, ptid_get_pid (main_ph.ptid));
   if (ptid_get_pid (inferior_ptid) == -1)
@@ -389,8 +388,6 @@ sol_thread_resume (struct target_ops *ops,
     }
 
   beneath->to_resume (beneath, ptid, step, signo);
-
-  do_cleanups (old_chain);
 }
 
 /* Wait for any threads to stop.  We may have to convert PTID from a
@@ -403,10 +400,9 @@ sol_thread_wait (struct target_ops *ops,
   ptid_t rtnval;
   ptid_t save_ptid;
   struct target_ops *beneath = find_target_beneath (ops);
-  struct cleanup *old_chain;
 
   save_ptid = inferior_ptid;
-  old_chain = save_inferior_ptid ();
+  scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
 
   inferior_ptid = thread_to_lwp (inferior_ptid, ptid_get_pid (main_ph.ptid));
   if (ptid_get_pid (inferior_ptid) == -1)
@@ -445,8 +441,6 @@ sol_thread_wait (struct target_ops *ops,
      package being initialized, since that can only happen after we've
      found the shared libs.  */
 
-  do_cleanups (old_chain);
-
   return rtnval;
 }
 
@@ -569,11 +563,9 @@ sol_thread_xfer_partial (struct target_ops *ops, enum target_object object,
 			  const gdb_byte *writebuf,
 			 ULONGEST offset, ULONGEST len, ULONGEST *xfered_len)
 {
-  enum target_xfer_status retval;
-  struct cleanup *old_chain;
   struct target_ops *beneath = find_target_beneath (ops);
 
-  old_chain = save_inferior_ptid ();
+  scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
 
   if (ptid_tid_p (inferior_ptid) || !target_thread_alive (inferior_ptid))
     {
@@ -585,12 +577,8 @@ sol_thread_xfer_partial (struct target_ops *ops, enum target_object object,
       inferior_ptid = procfs_first_available ();
     }
 
-  retval = beneath->to_xfer_partial (beneath, object, annex, readbuf,
-				     writebuf, offset, len, xfered_len);
-
-  do_cleanups (old_chain);
-
-  return retval;
+  return beneath->to_xfer_partial (beneath, object, annex, readbuf,
+				   writebuf, offset, len, xfered_len);
 }
 
 static void
@@ -800,9 +788,8 @@ rw_common (int dowrite, const struct ps_prochandle *ph, gdb_ps_addr_t addr,
 	   gdb_byte *buf, int size)
 {
   int ret;
-  struct cleanup *old_chain;
 
-  old_chain = save_inferior_ptid ();
+  scoped_restore save_inferior_ptid = make_scoped_restore (&inferior_ptid);
 
   if (ptid_tid_p (inferior_ptid) || !target_thread_alive (inferior_ptid))
     {
@@ -826,8 +813,6 @@ rw_common (int dowrite, const struct ps_prochandle *ph, gdb_ps_addr_t addr,
   else
     ret = target_read_memory (addr, (gdb_byte *) buf, size);
 
-  do_cleanups (old_chain);
-
   return (ret == 0 ? PS_OK : PS_ERR);
 }