* 41intnam.ads, 42intnam.ads, 4aintnam.ads, 4cintnam.ads,

	4dintnam.ads, 4gintnam.ads, 4hintnam.ads, 4lintnam.ads,
	4mintnam.ads, 4pintnam.ads, 4rintnam.ads, 4sintnam.ads,
	4uintnam.ads, 4vcalend.adb, 4zintnam.ads, 52system.ads,
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	5avxwork.ads, 5bosinte.adb, 5bsystem.ads, 5esystem.ads,
	5fsystem.ads, 5ftaprop.adb, 5ginterr.adb, 5gmastop.adb,
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	5itaprop.adb, 5ksystem.ads, 5kvxwork.ads, 5lintman.adb,
	5lsystem.ads, 5mvxwork.ads, 5ninmaop.adb, 5nosinte.ads,
	5ntaprop.adb, 5ointerr.adb, 5omastop.adb, 5oosinte.adb,
	5osystem.ads, 5otaprop.adb, 5otaspri.ads, 5pvxwork.ads,
	5qtaprop.adb, 5sintman.adb, 5ssystem.ads, 5staprop.adb,
	5stpopse.adb, 5svxwork.ads, 5tosinte.ads, 5uintman.adb,
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	5vmastop.adb, 5vparame.ads, 5vsystem.ads, 5vtaprop.adb,
	5vtpopde.adb, 5wmemory.adb, 5wsystem.ads, 5wtaprop.adb,
	5ysystem.ads, 5zinterr.adb, 5zintman.adb, 5zosinte.adb,
	5zosinte.ads, 5zsystem.ads, 5ztaprop.adb, 6vcpp.adb, 6vcstrea.adb,
	7sintman.adb, 7staprop.adb, 7stpopsp.adb, 9drpc.adb,
	Make-lang.in, Makefile.in, a-caldel.adb, a-comlin.ads,
	a-dynpri.adb, a-except.adb, a-except.ads, a-finali.adb,
	a-ncelfu.ads, a-reatim.adb, a-retide.adb, a-stream.ads,
	a-ststio.adb, a-ststio.ads, a-stwifi.adb, a-tags.adb, a-tasatt.adb,
	a-textio.adb, a-tideau.adb, a-tiflau.adb, a-tigeau.adb,
	a-tigeau.ads, a-tiinau.adb, a-timoau.adb, a-witeio.adb,
	a-wtdeau.adb, a-wtenau.adb, a-wtflau.adb, a-wtgeau.adb,
	a-wtgeau.ads, a-wtinau.adb, a-wtmoau.adb, ada-tree.def, ada-tree.h,
	adaint.c, adaint.h, ali-util.adb, ali.adb, ali.ads, atree.adb,
	atree.ads, atree.h, back_end.adb, bcheck.adb, bindgen.adb,
	bindusg.adb, checks.adb, comperr.adb, config-lang.in, csets.adb,
	csets.ads, cstand.adb, cstreams.c, debug.adb, debug.ads, decl.c,
	einfo.adb, einfo.ads, einfo.h, elists.h, errout.adb, errout.ads,
	eval_fat.adb, exp_aggr.adb, exp_attr.adb, exp_ch11.adb,
	exp_ch12.adb, exp_ch13.adb, exp_ch2.adb, exp_ch3.adb, exp_ch3.ads,
	exp_ch4.adb, exp_ch5.adb, exp_ch6.adb, exp_ch7.adb, exp_ch7.ads,
	exp_ch9.adb, exp_ch9.ads, exp_dbug.adb, exp_dbug.ads, exp_disp.ads,
	exp_dist.adb, exp_fixd.adb, exp_intr.adb, exp_pakd.adb,
	exp_prag.adb, exp_strm.adb, exp_util.adb, exp_util.ads,
	expander.adb, expect.c, fe.h, fmap.adb, fmap.ads, fname-uf.adb,
	freeze.adb, frontend.adb, g-awk.adb, g-cgideb.adb, g-comlin.adb,
	g-comlin.ads, g-debpoo.adb, g-dirope.adb, g-dirope.ads,
	g-dyntab.adb, g-expect.adb, g-expect.ads, g-io.ads, g-io_aux.adb,
	g-io_aux.ads, g-locfil.adb, g-locfil.ads, g-os_lib.adb,
	g-os_lib.ads, g-regexp.adb, g-regpat.adb, g-socket.adb,
	g-socket.ads, g-spipat.adb, g-table.adb, g-trasym.adb,
	g-trasym.ads, gigi.h, gmem.c, gnat1drv.adb, gnatbind.adb, gnatbl.c,
	gnatchop.adb, gnatcmd.adb, gnatdll.adb, gnatfind.adb, gnatlbr.adb,
	gnatlink.adb, gnatls.adb, gnatmem.adb, gnatprep.adb, gnatvsn.ads,
	gnatxref.adb, hlo.adb, hostparm.ads, i-cobol.adb, i-cpp.adb,
	i-cstrea.ads, i-cstrin.adb, i-pacdec.adb, i-vxwork.ads,
	impunit.adb, init.c, inline.adb, io-aux.c, layout.adb, lib-load.adb,
	lib-util.adb, lib-writ.adb, lib-writ.ads, lib-xref.adb,
	lib-xref.ads, lib.adb, lib.ads, make.adb, makeusg.adb, mdll.adb,
	memroot.adb, misc.c, mlib-tgt.adb, mlib-utl.adb, mlib-utl.ads,
	mlib.adb, namet.adb, namet.ads, namet.h, nlists.h, nmake.adb,
	nmake.ads, nmake.adt, opt.adb, opt.ads, osint.adb, osint.ads,
	output.adb, output.ads, par-ch2.adb, par-ch3.adb, par-ch5.adb,
	par-prag.adb, par-tchk.adb, par-util.adb, par.adb, prj-attr.adb,
	prj-dect.adb, prj-env.adb, prj-env.ads, prj-nmsc.adb, prj-part.adb,
	prj-proc.adb, prj-strt.adb, prj-tree.adb, prj-tree.ads, prj.adb,
	prj.ads, raise.c, raise.h, repinfo.adb, restrict.adb, restrict.ads,
	rident.ads, rtsfind.adb, rtsfind.ads, s-arit64.adb, s-asthan.adb,
	s-atacco.adb, s-atacco.ads, s-auxdec.adb, s-crc32.adb, s-crc32.ads,
	s-direio.adb, s-fatgen.adb, s-fileio.adb, s-finimp.adb,
	s-gloloc.adb, s-gloloc.ads, s-interr.adb, s-mastop.adb,
	s-mastop.ads, s-memory.adb, s-parame.ads, s-parint.adb,
	s-pooglo.adb, s-pooloc.adb, s-rpc.adb, s-secsta.adb, s-sequio.adb,
	s-shasto.adb, s-soflin.adb, s-soflin.ads, s-stache.adb,
	s-taasde.adb, s-taasde.ads, s-tadeca.adb, s-tadeca.ads,
	s-tadert.adb, s-tadert.ads, s-taenca.adb, s-taenca.ads,
	s-taprob.adb, s-taprop.ads, s-tarest.adb, s-tasdeb.adb,
	s-tasini.adb, s-tasini.ads, s-taskin.adb, s-taskin.ads,
	s-tasque.adb, s-tasque.ads, s-tasren.adb, s-tasren.ads,
	s-tassta.adb, s-tasuti.adb, s-tasuti.ads, s-tataat.adb,
	s-tataat.ads, s-tpoben.adb, s-tpoben.ads, s-tpobop.adb,
	s-tposen.adb, s-tposen.ads, s-traceb.adb, s-traceb.ads,
	s-unstyp.ads, s-widenu.adb, scn-nlit.adb, scn.adb, sem.adb,
	sem_aggr.adb, sem_attr.adb, sem_attr.ads, sem_case.adb,
	sem_ch10.adb, sem_ch11.adb, sem_ch11.ads, sem_ch12.adb,
	sem_ch13.adb, sem_ch13.ads, sem_ch2.adb, sem_ch3.adb, sem_ch3.ads,
	sem_ch4.adb, sem_ch5.adb, sem_ch6.adb, sem_ch6.ads, sem_ch7.adb,
	sem_ch8.adb, sem_ch8.ads, sem_ch9.adb, sem_disp.adb, sem_dist.adb,
	sem_elab.adb, sem_elim.adb, sem_elim.ads, sem_eval.adb,
	sem_intr.adb, sem_mech.adb, sem_prag.adb, sem_res.adb,
	sem_type.adb, sem_util.adb, sem_util.ads, sem_vfpt.adb,
	sem_warn.adb, sinfo.adb, sinfo.ads, sinfo.h, sinput-l.adb,
	sinput-l.ads, sinput.adb, sinput.ads, snames.adb, snames.ads,
	snames.h, sprint.adb, sprint.ads, stringt.adb, stringt.ads,
	stringt.h, style.adb, switch.adb, switch.ads, sysdep.c, system.ads,
	table.adb, targparm.adb, targparm.ads, targtyps.c, tbuild.adb,
	tbuild.ads, tracebak.c, trans.c, tree_gen.adb, tree_io.adb,
	treepr.adb, treepr.ads, treeprs.ads, treeprs.adt, ttypes.ads,
	types.adb, types.ads, types.h, uintp.ads, urealp.ads, usage.adb,
	utils.c, utils2.c, validsw.adb, xnmake.adb, xr_tabls.adb,
	xr_tabls.ads, xref_lib.adb, xref_lib.ads : Merge in ACT changes.

	* 1ssecsta.adb, 1ssecsta.ads, a-chlat9.ads, a-cwila9.ads,
	g-enblsp.adb, g-md5.adb, g-md5.ads, gnatname.adb, gnatname.ads,
	mkdir.c, osint-b.adb, osint-b.ads, osint-c.adb, osint-c.ads,
	osint-l.adb, osint-l.ads, osint-m.adb, osint-m.ads : New files

	* 3lsoccon.ads, 5qparame.ads, 5qvxwork.ads, 5smastop.adb,
	5zparame.ads, gnatmain.adb, gnatmain.ads, gnatpsys.adb : Removed

	* mdllfile.adb, mdllfile.ads, mdlltool.adb, mdlltool.ads : Renamed
	to mdll-fil.ad[bs] and mdll-util.ad[bs]

	* mdll-fil.adb, mdll-fil.ads, mdll-utl.adb, mdll-utl.ads : Renamed
	from mdllfile.ad[bs] and mdlltool.ad[bs]


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@50451 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 122 insertions, 46 deletions

diff --git a/gcc/ada/sem_warn.adb b/gcc/ada/sem_warn.adb
index c6107e49e9b..eb7af5d4634 100644
--- a/gcc/ada/sem_warn.adb
+++ b/gcc/ada/sem_warn.adb
@@ -8,7 +8,7 @@
 --                                                                          --
 --                            $Revision$
 --                                                                          --
---          Copyright (C) 1999-2001 Free Software Foundation, Inc.          --
+--          Copyright (C) 1999-2002 Free Software Foundation, Inc.          --
 --                                                                          --
 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
 -- terms of the  GNU General Public License as published  by the Free Soft- --
@@ -120,11 +120,11 @@ package body Sem_Warn is
      Table_Increment      => Alloc.Conditional_Stack_Increment,
      Table_Name           => "Conditional_Stack");
 
-   Current_Entity_List : Elist_Id := No_Elist;
-   --  This is a copy of the Defs list of the current branch of the current
-   --  conditional. It could be accessed by taking the top element of the
-   --  Conditional_Stack, and going to te Current_Branch entry of this
-   --  conditional, but we keep it precomputed for rapid access.
+   function Operand_Has_Warnings_Suppressed (N : Node_Id) return Boolean;
+   --  This function traverses the expression tree represented by the node
+   --  N and determines if any sub-operand is a reference to an entity for
+   --  which the Warnings_Off flag is set. True is returned if such an
+   --  entity is encountered, and False otherwise.
 
    ----------------------
    -- Check_References --
@@ -142,8 +142,7 @@ package body Sem_Warn is
       function Publicly_Referenceable (Ent : Entity_Id) return Boolean;
       --  This is true if the entity in question is potentially referenceable
       --  from another unit. This is true for entities in packages that are
-      --  at the library level, or for entities in tasks or protected objects
-      --  that are themselves publicly visible.
+      --  at the library level.
 
       ----------------------------
       -- Output_Reference_Error --
@@ -192,32 +191,47 @@ package body Sem_Warn is
       ----------------------------
 
       function Publicly_Referenceable (Ent : Entity_Id) return Boolean is
-         S : Entity_Id;
+         P : Node_Id;
 
       begin
-         --  Any entity in a generic package is considered to be publicly
-         --  referenceable, since it could be referenced in an instantiation
+         --  Examine parents to look for a library level package spec
+         --  But if we find a body or block or other similar construct
+         --  along the way, we cannot be referenced.
 
-         if Ekind (E) = E_Generic_Package then
-            return True;
-         end if;
+         P := Parent (Ent);
+         loop
+            case Nkind (P) is
 
-         --  Otherwise look up the scope stack
+               --  If we get to top of tree, then publicly referencable
 
-         S := Scope (Ent);
-         loop
-            if Is_Package (S) then
-               return Is_Library_Level_Entity (S);
+               when N_Empty =>
+                  return True;
 
-            elsif Ekind (S) = E_Task_Type
-              or else Ekind (S) = E_Protected_Type
-              or else Ekind (S) = E_Entry
-            then
-               S := Scope (S);
+               --  If we reach a generic package declaration, then always
+               --  consider this referenceable, since any instantiation will
+               --  have access to the entities in the generic package. Note
+               --  that the package itself may not be instantiated, but then
+               --  we will get a warning for the package entity
 
-            else
-               return False;
-            end if;
+               when N_Generic_Package_Declaration =>
+                  return True;
+
+               --  If we reach any body, then definitely not referenceable
+
+               when N_Package_Body    |
+                    N_Subprogram_Body |
+                    N_Task_Body       |
+                    N_Entry_Body      |
+                    N_Protected_Body  |
+                    N_Block_Statement |
+                    N_Subunit         =>
+                  return False;
+
+               --  For all other cases, keep looking up tree
+
+               when others =>
+                  P := Parent (P);
+            end case;
          end loop;
       end Publicly_Referenceable;
 
@@ -233,7 +247,7 @@ package body Sem_Warn is
       --  necessary to suppress the warnings in this case).
 
       if Warning_Mode = Suppress
-        or else Errors_Detected /= 0
+        or else Serious_Errors_Detected /= 0
         or else Unloaded_Subunits
       then
          return;
@@ -340,13 +354,13 @@ package body Sem_Warn is
 
             --  Then check for unreferenced variables
 
-            if Check_Unreferenced
+            if not Referenced (E1)
 
-               --  Check entity is flagged as not referenced and that
-               --  warnings are not suppressed for this entity
+               --  Check that warnings on unreferenced entities are enabled
 
-               and then not Referenced (E1)
-               and then not Warnings_Off (E1)
+              and then ((Check_Unreferenced and then not Is_Formal (E1))
+                           or else
+                        (Check_Unreferenced_Formals and then Is_Formal (E1)))
 
                --  Warnings are placed on objects, types, subprograms,
                --  labels, and enumeration literals.
@@ -363,7 +377,7 @@ package body Sem_Warn is
                            or else
                          Is_Overloadable (E1))
 
-               --  We only place warnings for the main unit
+               --  We only place warnings for the extended main unit
 
                and then In_Extended_Main_Source_Unit (E1)
 
@@ -372,16 +386,19 @@ package body Sem_Warn is
 
                and then Instantiation_Location (Sloc (E1)) = No_Location
 
-               --  Exclude formal parameters from bodies (in the case
-               --  where there is a separate spec, it is the spec formals
-               --  that are of interest).
+               --  Exclude formal parameters from bodies if the corresponding
+               --  spec entity has been referenced in the case where there is
+               --  a separate spec.
 
-               and then (not Is_Formal (E1)
-                           or else
-                         Ekind (Scope (E1)) /= E_Subprogram_Body)
+               and then not (Is_Formal (E1)
+                               and then
+                             Ekind (Scope (E1)) = E_Subprogram_Body
+                               and then
+                             Present (Spec_Entity (E1))
+                               and then
+                             Referenced (Spec_Entity (E1)))
 
-               --  Consider private type referenced if full view is
-               --  referenced.
+               --  Consider private type referenced if full view is referenced
 
                and then not (Is_Private_Type (E1)
                                and then
@@ -417,6 +434,13 @@ package body Sem_Warn is
                              and then Ekind (E1) /= E_Constant
                              and then Ekind (E1) /= E_Component)
                            or else not Is_Task_Type (Etype (E1)))
+
+               --  For subunits, only place warnings on the main unit
+               --  itself, since parent units are not completely compiled
+
+               and then (Nkind (Unit (Cunit (Main_Unit))) /= N_Subunit
+                           or else
+                         Get_Source_Unit (E1) = Main_Unit)
             then
                --  Suppress warnings in internal units if not in -gnatg
                --  mode (these would be junk warnings for an applications
@@ -891,6 +915,53 @@ package body Sem_Warn is
       end if;
    end Check_Unused_Withs;
 
+   -------------------------------------
+   -- Operand_Has_Warnings_Suppressed --
+   -------------------------------------
+
+   function Operand_Has_Warnings_Suppressed (N : Node_Id) return Boolean is
+
+      function Check_For_Warnings (N : Node_Id) return Traverse_Result;
+      --  Function used to check one node to see if it is or was originally
+      --  a reference to an entity for which Warnings are off. If so, Abandon
+      --  is returned, otherwise OK_Orig is returned to continue the traversal
+      --  of the original expression.
+
+      function Traverse is new Traverse_Func (Check_For_Warnings);
+      --  Function used to traverse tree looking for warnings
+
+      ------------------------
+      -- Check_For_Warnings --
+      ------------------------
+
+      function Check_For_Warnings (N : Node_Id) return Traverse_Result is
+         R : constant Node_Id := Original_Node (N);
+
+      begin
+         if Nkind (R) in N_Has_Entity
+           and then Present (Entity (R))
+           and then Warnings_Off (Entity (R))
+         then
+            return Abandon;
+         else
+            return OK_Orig;
+         end if;
+      end Check_For_Warnings;
+
+   --  Start of processing for Operand_Has_Warnings_Suppressed
+
+   begin
+      return Traverse (N) = Abandon;
+
+   --  If any exception occurs, then something has gone wrong, and this is
+   --  only a minor aesthetic issue anyway, so just say we did not find what
+   --  we are looking for, rather than blow up.
+
+   exception
+      when others =>
+         return False;
+   end Operand_Has_Warnings_Suppressed;
+
    ----------------------------------
    -- Output_Unreferenced_Messages --
    ----------------------------------
@@ -1017,10 +1088,15 @@ package body Sem_Warn is
             P := Parent (P);
          end loop;
 
-         if Entity (C) = Standard_True then
-            Error_Msg_N ("condition is always True?", C);
-         else
-            Error_Msg_N ("condition is always False?", C);
+         --  Here we issue the warning unless some sub-operand has warnings
+         --  set off, in which case we suppress the warning for the node.
+
+         if not Operand_Has_Warnings_Suppressed (C) then
+            if Entity (C) = Standard_True then
+               Error_Msg_N ("condition is always True?", C);
+            else
+               Error_Msg_N ("condition is always False?", C);
+            end if;
          end if;
       end if;
    end Warn_On_Known_Condition;