2007-10-15 Robert Dewar <dewar@adacore.com>

	* s-taprop-solaris.adb, s-taprop-vms.adb, s-taprop-mingw.adb, 
	s-taprop-vxworks.adb, s-taprop-posix.adb, a-calend-vms.adb,
	a-calend.adb, a-nuflra.adb, a-tigeau.adb, a-wtgeau.adb, 
	checks.adb, bindgen.adb, eval_fat.adb, exp_fixd.adb, fmap.adb, 
	freeze.adb, g-awk.adb, g-calend.adb, g-diopit.adb, g-expect.adb, 
	gnatchop.adb, gnatlink.adb, g-spipat.adb, g-thread.adb, make.adb, 
	mdll.adb, mlib.adb, mlib-prj.adb, osint.adb, par-ch3.adb, prj.adb, 
	prj-makr.adb, sem_prag.adb, sem_type.adb, s-fatgen.adb, s-fileio.adb, 
	sinfo.ads, sinput-d.adb, s-taasde.adb, s-tasdeb.ads, s-tasren.adb, 
	s-tassta.adb, s-tpobop.adb, s-tposen.adb, stylesw.adb, types.ads,
	uintp.adb, validsw.adb, makegpr.adb, a-rbtgso.adb, a-crbtgo.adb, 
	a-coorse.adb, a-convec.adb, a-coinve.adb, a-cohama.adb, a-ciorse.adb, 
	a-cihama.adb, a-cidlli.adb, a-chtgop.adb, a-cdlili.adb, a-cdlili.adb, 
	a-coormu.adb, a-ciormu.adb, a-cihase.adb, a-cohase.adb, a-ciorma.adb, 
	a-coorma.adb, a-ztgeau.adb, symbols-vms.adb, a-crdlli.adb, 
	a-calari.adb, a-calfor.adb, s-os_lib.adb, s-regpat.adb, a-ngrear.adb:
	Minor reformatting.
	Add Unreferenced and Warnings (Off) pragmas for cases of
	variables modified calls where they are IN OUT or OUT parameters and
	the resulting values are not subsequently referenced. In a few cases,
	we also remove redundant code found by the new warnings.

	* ug_words, vms_data.ads, usage.adb, sem_util.adb, sem_util.ads, 
	sem_warn.adb, sem_warn.ads, sem_res.adb, sem_ch7.adb, sem_ch8.adb,
	sem_ch5.adb, opt.ads, lib-xref.adb, lib-xref.ads, exp_smem.adb,
	sem_ch11.adb, exp_ch6.adb, einfo.ads, einfo.adb: implement a new
	warning controlled by -gnatw.o that warns on cases of out parameter
	values being ignored.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@129318 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 73 insertions, 60 deletions

diff --git a/gcc/ada/s-tpobop.adb b/gcc/ada/s-tpobop.adb
index 25208ad10c0..f034f9e63a5 100644
--- a/gcc/ada/s-tpobop.adb
+++ b/gcc/ada/s-tpobop.adb
@@ -114,11 +114,10 @@ package body System.Tasking.Protected_Objects.Operations is
      (Entry_Call : Entry_Call_Link;
       With_Abort : Boolean);
    pragma Inline (Update_For_Queue_To_PO);
-   --  Update the state of an existing entry call to reflect
-   --  the fact that it is being enqueued, based on
-   --  whether the current queuing action is with or without abort.
-   --  Call this only while holding the PO's lock.
-   --  It returns with the PO's lock still held.
+   --  Update the state of an existing entry call to reflect the fact that it
+   --  is being enqueued, based on whether the current queuing action is with
+   --  or without abort. Call this only while holding the PO's lock. It returns
+   --  with the PO's lock still held.
 
    procedure Requeue_Call
      (Self_Id    : Task_Id;
@@ -132,15 +131,16 @@ package body System.Tasking.Protected_Objects.Operations is
    -- Cancel_Protected_Entry_Call --
    ---------------------------------
 
-   --  Compiler interface only.  Do not call from within the RTS.
-   --  This should have analogous effect to Cancel_Task_Entry_Call,
-   --  setting the value of Block.Cancelled instead of returning
-   --  the parameter value Cancelled.
+   --  Compiler interface only (do not call from within the RTS)
+
+   --  This should have analogous effect to Cancel_Task_Entry_Call, setting
+   --  the value of Block.Cancelled instead of returning the parameter value
+   --  Cancelled.
 
-   --  The effect should be idempotent, since the call may already
-   --  have been dequeued.
+   --  The effect should be idempotent, since the call may already have been
+   --  dequeued.
 
-   --  source code:
+   --  Source code:
 
    --      select r.e;
    --         ...A...
@@ -148,12 +148,13 @@ package body System.Tasking.Protected_Objects.Operations is
    --         ...B...
    --      end select;
 
-   --  expanded code:
+   --  Expanded code:
 
    --      declare
    --         X : protected_entry_index := 1;
    --         B80b : communication_block;
    --         communication_blockIP (B80b);
+
    --      begin
    --         begin
    --            A79b : label
@@ -165,6 +166,7 @@ package body System.Tasking.Protected_Objects.Operations is
    --                  end if;
    --                  return;
    --               end _clean;
+
    --            begin
    --               protected_entry_call (rTV!(r)._object'unchecked_access, X,
    --                 null_address, asynchronous_call, B80b, objectF => 0);
@@ -174,11 +176,13 @@ package body System.Tasking.Protected_Objects.Operations is
    --            at end
    --               _clean;
    --            end A79b;
+
    --         exception
    --            when _abort_signal =>
    --               abort_undefer.all;
    --               null;
    --         end;
+
    --         if not cancelled (B80b) then
    --            x := ...A...
    --         end if;
@@ -188,12 +192,12 @@ package body System.Tasking.Protected_Objects.Operations is
    --  Abort_Signal should be raised and ATC will take us to the at-end
    --  handler, which will call _clean.
 
-   --  If the entry call returns with the call already completed,
-   --  we can skip this, and use the "if enqueued()" to go past
-   --  the at-end handler, but we will still call _clean.
+   --  If the entry call returns with the call already completed, we can skip
+   --  this, and use the "if enqueued()" to go past the at-end handler, but we
+   --  will still call _clean.
 
-   --  If the abortable part completes before the entry call is Done,
-   --  it will call _clean.
+   --  If the abortable part completes before the entry call is Done, it will
+   --  call _clean.
 
    --  If the entry call or the abortable part raises an exception,
    --  we will still call _clean, but the value of Cancelled should not matter.
@@ -201,24 +205,21 @@ package body System.Tasking.Protected_Objects.Operations is
    --  Whoever calls _clean first gets to decide whether the call
    --  has been "cancelled".
 
-   --  Enqueued should be true if there is any chance that the call
-   --  is still on a queue. It seems to be safe to make it True if
-   --  the call was Onqueue at some point before return from
-   --  Protected_Entry_Call.
+   --  Enqueued should be true if there is any chance that the call is still on
+   --  a queue. It seems to be safe to make it True if the call was Onqueue at
+   --  some point before return from Protected_Entry_Call.
 
    --  Cancelled should be true iff the abortable part completed
    --  and succeeded in cancelling the entry call before it completed.
 
    --  ?????
-   --  The need for Enqueued is less obvious.
-   --  The "if enqueued ()" tests are not necessary, since both
-   --  Cancel_Protected_Entry_Call and Protected_Entry_Call must
-   --  do the same test internally, with locking. The one that
-   --  makes cancellation conditional may be a useful heuristic
-   --  since at least 1/2 the time the call should be off-queue
-   --  by that point. The other one seems totally useless, since
-   --  Protected_Entry_Call must do the same check and then
-   --  possibly wait for the call to be abortable, internally.
+   --  The need for Enqueued is less obvious. The "if enqueued ()" tests are
+   --  not necessary, since Cancel_Protected_Entry_Call/Protected_Entry_Call
+   --  must do the same test internally, with locking. The one that makes
+   --  cancellation conditional may be a useful heuristic since at least 1/2
+   --  the time the call should be off-queue by that point. The other one seems
+   --  totally useless, since Protected_Entry_Call must do the same check and
+   --  then possibly wait for the call to be abortable, internally.
 
    --  We can check Call.State here without locking the caller's mutex,
    --  since the call must be over after returning from Wait_For_Completion.
@@ -277,15 +278,17 @@ package body System.Tasking.Protected_Objects.Operations is
       pragma Debug
        (Debug.Trace (STPO.Self, "Exceptional_Complete_Entry_Body", 'P'));
 
-      --  We must have abort deferred, since we are inside
-      --  a protected operation.
+      --  We must have abort deferred, since we are inside a protected
+      --  operation.
 
       if Entry_Call /= null then
-         --  The call was not requeued.
+
+         --  The call was not requeued
 
          Entry_Call.Exception_To_Raise := Ex;
 
          if Ex /= Ada.Exceptions.Null_Id then
+
             --  An exception was raised and abort was deferred, so adjust
             --  before propagating, otherwise the task will stay with deferral
             --  enabled for its remaining life.
@@ -299,6 +302,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
          --  Wakeup_Entry_Caller will be called from PO_Do_Or_Queue or
          --  PO_Service_Entries on return.
+
       end if;
 
       if Runtime_Traces then
@@ -331,7 +335,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
       if Barrier_Value then
 
-         --  Not abortable while service is in progress.
+         --  Not abortable while service is in progress
 
          if Entry_Call.State = Now_Abortable then
             Entry_Call.State := Was_Abortable;
@@ -439,7 +443,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
          E := Protected_Entry_Index (Entry_Call.E);
 
-         --  Not abortable while service is in progress.
+         --  Not abortable while service is in progress
 
          if Entry_Call.State = Now_Abortable then
             Entry_Call.State := Was_Abortable;
@@ -454,10 +458,12 @@ package body System.Tasking.Protected_Objects.Operations is
             end if;
 
             pragma Debug
-             (Debug.Trace (Self_ID, "POSE: start entry body", 'P'));
-            Object.Entry_Bodies (
-              Object.Find_Body_Index (Object.Compiler_Info, E)).Action (
-                Object.Compiler_Info, Entry_Call.Uninterpreted_Data, E);
+              (Debug.Trace (Self_ID, "POSE: start entry body", 'P'));
+
+            Object.Entry_Bodies
+              (Object.Find_Body_Index (Object.Compiler_Info, E)).Action
+                (Object.Compiler_Info, Entry_Call.Uninterpreted_Data, E);
+
          exception
             when others =>
                Queuing.Broadcast_Program_Error
@@ -497,8 +503,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
    function Protected_Count
      (Object : Protection_Entries'Class;
-      E      : Protected_Entry_Index)
-      return   Natural
+      E      : Protected_Entry_Index) return Natural
    is
    begin
       return Queuing.Count_Waiting (Object.Entry_Queues (E));
@@ -508,7 +513,7 @@ package body System.Tasking.Protected_Objects.Operations is
    -- Protected_Entry_Call --
    --------------------------
 
-   --  Compiler interface only.  Do not call from within the RTS.
+   --  Compiler interface only (do not call from within the RTS)
 
    --  select r.e;
    --     ...A...
@@ -520,9 +525,11 @@ package body System.Tasking.Protected_Objects.Operations is
    --     X : protected_entry_index := 1;
    --     B85b : communication_block;
    --     communication_blockIP (B85b);
+
    --  begin
    --     protected_entry_call (rTV!(r)._object'unchecked_access, X,
    --       null_address, conditional_call, B85b, objectF => 0);
+
    --     if cancelled (B85b) then
    --        ...B...
    --     else
@@ -636,7 +643,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
       if Entry_Call.State >= Done then
 
-         --  Once State >= Done it will not change any more.
+         --  Once State >= Done it will not change any more
 
          if Single_Lock then
             STPO.Lock_RTS;
@@ -657,16 +664,17 @@ package body System.Tasking.Protected_Objects.Operations is
          return;
 
       else
-         --  In this case we cannot conclude anything,
-         --  since State can change concurrently.
+         --  In this case we cannot conclude anything, since State can change
+         --  concurrently.
+
          null;
       end if;
 
-      --  Now for the general case.
+      --  Now for the general case
 
       if Mode = Asynchronous_Call then
 
-         --  Try to avoid an expensive call.
+         --  Try to avoid an expensive call
 
          if not Initially_Abortable then
             if Single_Lock then
@@ -686,6 +694,7 @@ package body System.Tasking.Protected_Objects.Operations is
             STPO.Lock_RTS;
             Entry_Calls.Wait_For_Completion (Entry_Call);
             STPO.Unlock_RTS;
+
          else
             STPO.Write_Lock (Self_ID);
             Entry_Calls.Wait_For_Completion (Entry_Call);
@@ -750,8 +759,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
             if Ceiling_Violation then
                Object.Call_In_Progress := null;
-               Queuing.Broadcast_Program_Error
-                 (Self_Id, Object, Entry_Call);
+               Queuing.Broadcast_Program_Error (Self_Id, Object, Entry_Call);
 
             else
                PO_Do_Or_Queue (Self_Id, New_Object, Entry_Call);
@@ -761,17 +769,17 @@ package body System.Tasking.Protected_Objects.Operations is
          else
             --  Requeue is to same protected object
 
-            --  ??? Try to compensate apparent failure of the
-            --  scheduler on some OS (e.g VxWorks) to give higher
-            --  priority tasks a chance to run (see CXD6002).
+            --  ??? Try to compensate apparent failure of the scheduler on some
+            --  OS (e.g VxWorks) to give higher priority tasks a chance to run
+            --  (see CXD6002).
 
             STPO.Yield (False);
 
             if Entry_Call.With_Abort
               and then Entry_Call.Cancellation_Attempted
             then
-               --  If this is a requeue with abort and someone tried
-               --  to cancel this call, cancel it at this point.
+               --  If this is a requeue with abort and someone tried to cancel
+               --  this call, cancel it at this point.
 
                Entry_Call.State := Cancelled;
                return;
@@ -804,6 +812,7 @@ package body System.Tasking.Protected_Objects.Operations is
                   if Single_Lock then
                      STPO.Unlock_RTS;
                   end if;
+
                else
                   Queuing.Enqueue
                     (New_Object.Entry_Queues (E), Entry_Call);
@@ -831,7 +840,7 @@ package body System.Tasking.Protected_Objects.Operations is
    -- Requeue_Protected_Entry --
    -----------------------------
 
-   --  Compiler interface only.  Do not call from within the RTS.
+   --  Compiler interface only (do not call from within the RTS)
 
    --  entry e when b is
    --  begin
@@ -893,7 +902,7 @@ package body System.Tasking.Protected_Objects.Operations is
    -- Requeue_Task_To_Protected_Entry --
    -------------------------------------
 
-   --  Compiler interface only.
+   --  Compiler interface only (do not call from within the RTS)
 
    --    accept e1 do
    --      ...A...
@@ -902,6 +911,7 @@ package body System.Tasking.Protected_Objects.Operations is
 
    --    A79b : address;
    --    L78b : label
+
    --    begin
    --       accept_call (1, A79b);
    --       ...A...
@@ -910,6 +920,7 @@ package body System.Tasking.Protected_Objects.Operations is
    --       goto L78b;
    --       <<L78b>>
    --       complete_rendezvous;
+
    --    exception
    --       when all others =>
    --          exceptional_complete_rendezvous (get_gnat_exception);
@@ -951,7 +962,7 @@ package body System.Tasking.Protected_Objects.Operations is
    -- Timed_Protected_Entry_Call --
    --------------------------------
 
-   --  Compiler interface only.  Do not call from within the RTS.
+   --  Compiler interface only (do not call from within the RTS)
 
    procedure Timed_Protected_Entry_Call
      (Object                : Protection_Entries_Access;
@@ -964,7 +975,9 @@ package body System.Tasking.Protected_Objects.Operations is
       Self_Id           : constant Task_Id  := STPO.Self;
       Entry_Call        : Entry_Call_Link;
       Ceiling_Violation : Boolean;
-      Yielded           : Boolean;
+
+      Yielded : Boolean;
+      pragma Unreferenced (Yielded);
 
    begin
       if Self_Id.ATC_Nesting_Level = ATC_Level'Last then
@@ -1028,7 +1041,7 @@ package body System.Tasking.Protected_Objects.Operations is
          STPO.Write_Lock (Self_Id);
       end if;
 
-      --  Try to avoid waiting for completed or cancelled calls.
+      --  Try to avoid waiting for completed or cancelled calls
 
       if Entry_Call.State >= Done then
          Utilities.Exit_One_ATC_Level (Self_Id);