[Ada] Close file descriptors allocated for tty only once

2019-09-17  Vadim Godunko  <godunko@adacore.com>

gcc/ada/

	* libgnat/g-exptty.ads (Close_Input): New subprogram.
	* libgnat/g-exptty.adb (Close_Input): New subprogram.
	(Close): Move close of TTY to Close_Input.
	* terminals.c (__gnat_close_tty): Set file descriptors to
	invalid value after close.

From-SVN: r275783

gcc/ada/ChangeLog

 2019-09-17  Vadim Godunko  <godunko@adacore.com>
 
+	* libgnat/g-exptty.ads (Close_Input): New subprogram.
+	* libgnat/g-exptty.adb (Close_Input): New subprogram.
+	(Close): Move close of TTY to Close_Input.
+	* terminals.c (__gnat_close_tty): Set file descriptors to
+	invalid value after close.
+
+2019-09-17  Vadim Godunko  <godunko@adacore.com>
+
 	* libgnat/g-expect.adb (Expect_Internal): Try to call 'poll' few
 	times.
 

gcc/ada/libgnat/g-exptty.adb

@@ -74,9 +74,6 @@ package body GNAT.Expect.TTY is
       procedure Free_Process (Process : System.Address);
       pragma Import (C, Free_Process, "__gnat_free_process");
 
-      procedure Close_TTY (Process : System.Address);
-      pragma Import (C, Close_TTY, "__gnat_close_tty");
-
    begin
       --  If we haven't already closed the process
 
@@ -123,10 +120,6 @@ package body GNAT.Expect.TTY is
             Status := Descriptor.Exit_Status;
          end if;
 
-         if not On_Windows then
-            Close_TTY (Descriptor.Process);
-         end if;
-
          Free_Process (Descriptor.Process'Address);
          Descriptor.Process := System.Null_Address;
 
@@ -141,6 +134,47 @@ package body GNAT.Expect.TTY is
       Close (Descriptor, Status);
    end Close;
 
+   -----------------
+   -- Close_Input --
+   -----------------
+
+   overriding procedure Close_Input
+     (Descriptor : in out TTY_Process_Descriptor)
+   is
+      function TTY_FD
+        (Handle : System.Address) return GNAT.OS_Lib.File_Descriptor;
+      pragma Import (C, TTY_FD, "__gnat_tty_fd");
+
+      procedure Close_TTY (Process : System.Address);
+      pragma Import (C, Close_TTY, "__gnat_close_tty");
+
+   begin
+      if not On_Windows and then Descriptor.Process /= System.Null_Address then
+         --  Check whether input/output/error streams use master descriptor and
+         --  reset corresponding members.
+
+         if Descriptor.Input_Fd = TTY_FD (Descriptor.Process) then
+            Descriptor.Input_Fd := Invalid_FD;
+         end if;
+
+         if Descriptor.Output_Fd = TTY_FD (Descriptor.Process) then
+            Descriptor.Output_Fd := Invalid_FD;
+         end if;
+
+         if Descriptor.Error_Fd = TTY_FD (Descriptor.Process) then
+            Descriptor.Error_Fd := Invalid_FD;
+         end if;
+
+         --  Close master descriptor.
+
+         Close_TTY (Descriptor.Process);
+      end if;
+
+      --  Call parent's implementation to close all remaining descriptors.
+
+      Process_Descriptor (Descriptor).Close_Input;
+   end Close_Input;
+
    -----------------------------
    -- Close_Pseudo_Descriptor --
    -----------------------------

gcc/ada/libgnat/g-exptty.ads

@@ -134,6 +134,8 @@ private
       Cmd   : String;
       Args  : System.Address);
 
+   procedure Close_Input (Descriptor : in out TTY_Process_Descriptor);
+
    Still_Active : constant Integer := -1;
 
    type TTY_Process_Descriptor is new Process_Descriptor with record

gcc/ada/terminals.c

@@ -1648,8 +1648,8 @@ __gnat_new_tty (void)
  */
 void __gnat_close_tty (pty_desc* desc)
 {
-  if (desc->master_fd >= 0) close (desc->master_fd);
-  if (desc->slave_fd  >= 0) close (desc->slave_fd);
+  if (desc->master_fd >= 0) { close (desc->master_fd); desc->master_fd = -1; }
+  if (desc->slave_fd  >= 0) { close (desc->slave_fd);  desc->slave_fd  = -1; }
 }
 
 /* __gnat_tty_name - return slave side device name