einfo.adb (Has_Pragma_Unused): Create this function as a setter for a new flag294 (Set_Has_Pragma_Unused):...

2016-07-04  Justin Squirek  <squirek@adacore.com>

	* einfo.adb (Has_Pragma_Unused): Create this function as a setter
	for a new flag294 (Set_Has_Pragma_Unused): Create this procedure
	as a getter for flag294 (Write_Entity_Flags): Register the new
	flag with an alias
	* einfo.ads Add comment documenting Has_Pragma_Unused (flag294)
	and subsequent getter and setter declarations.
	* lib-xref.adb (Generate_Reference): Recognize Has_Pragma_Unused
	flag to print appropriate warning messages.
	* par-prag.adb (Prag): Classify Pragma_Unused into "All Other
	Pragmas."
	* snames.ads-tmpl Add a new name to the name constants and a
	new pramga to Pragma_Id for pramga Unused.
	* sem_prag.adb (Analyze_Pragma): Create case for Pragma_Unused
	and move the block for Pragma_Unmodified and Pragma_Unreferenced
	out and into local subprograms.
	(Analyze_Unmodified, Analyze_Unreferenced): From the old pragma blocks
	that have been separated in to local subprograms add a parameter to
	indicate the if they are being called in the context of Pragma_Unused
	and handle it accordingly.
	(Is_Non_Significant_Pragma_Reference): Add an entry for Pragma_Unused
	and correct the position of Pragma_Unevaluated_Use_Of_Old.
	* sem_util.adb (Note_Possible_Modification): Recognize
	Has_Pragma_Unused flag to print appropriate warning messages.

From-SVN: r237961

8 files changed, 399 insertions, 250 deletions

diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 6784eb2..bbd98c4 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,3 +1,29 @@
+2016-07-04  Justin Squirek  <squirek@adacore.com>
+
+	* einfo.adb (Has_Pragma_Unused): Create this function as a setter
+	for a new flag294 (Set_Has_Pragma_Unused): Create this procedure
+	as a getter for flag294 (Write_Entity_Flags): Register the new
+	flag with an alias
+	* einfo.ads Add comment documenting Has_Pragma_Unused (flag294)
+	and subsequent getter and setter declarations.
+	* lib-xref.adb (Generate_Reference): Recognize Has_Pragma_Unused
+	flag to print appropriate warning messages.
+	* par-prag.adb (Prag): Classify Pragma_Unused into "All Other
+	Pragmas."
+	* snames.ads-tmpl Add a new name to the name constants and a
+	new pramga to Pragma_Id for pramga Unused.
+	* sem_prag.adb (Analyze_Pragma): Create case for Pragma_Unused
+	and move the block for Pragma_Unmodified and Pragma_Unreferenced
+	out and into local subprograms.
+	(Analyze_Unmodified, Analyze_Unreferenced): From the old pragma blocks
+	that have been separated in to local subprograms add a parameter to
+	indicate the if they are being called in the context of Pragma_Unused
+	and handle it accordingly.
+	(Is_Non_Significant_Pragma_Reference): Add an entry for Pragma_Unused
+	and correct the position of Pragma_Unevaluated_Use_Of_Old.
+	* sem_util.adb (Note_Possible_Modification): Recognize
+	Has_Pragma_Unused flag to print appropriate warning messages.
+
 2016-07-04  Ed Schonberg  <schonberg@adacore.com>
 
 	* freeze.adb (Check_Inherited_Conditions): Perform two passes over
diff --git a/gcc/ada/einfo.adb b/gcc/ada/einfo.adb
index fd01315..ae4a3bb 100644
--- a/gcc/ada/einfo.adb
+++ b/gcc/ada/einfo.adb
@@ -608,8 +608,8 @@ package body Einfo is
    --    Has_Inherited_Invariants        Flag291
    --    Is_Partial_Invariant_Procedure  Flag292
    --    Is_Actual_Subtype               Flag293
+   --    Has_Pragma_Unused               Flag294
 
-   --    (unused)                        Flag294
    --    (unused)                        Flag295
    --    (unused)                        Flag296
    --    (unused)                        Flag297
@@ -1761,6 +1761,11 @@ package body Einfo is
       return Flag212 (Id);
    end Has_Pragma_Unreferenced_Objects;
 
+   function Has_Pragma_Unused (Id : E) return B is
+   begin
+      return Flag294 (Id);
+   end Has_Pragma_Unused;
+
    function Has_Predicates (Id : E) return B is
    begin
       pragma Assert (Is_Type (Id));
@@ -4768,6 +4773,11 @@ package body Einfo is
       Set_Flag212 (Id, V);
    end Set_Has_Pragma_Unreferenced_Objects;
 
+   procedure Set_Has_Pragma_Unused (Id : E; V : B := True) is
+   begin
+      Set_Flag294 (Id, V);
+   end Set_Has_Pragma_Unused;
+
    procedure Set_Has_Predicates (Id : E; V : B := True) is
    begin
       pragma Assert (Is_Type (Id) or else Ekind (Id) = E_Void);
@@ -9162,6 +9172,7 @@ package body Einfo is
       W ("Has_Pragma_Unmodified",           Flag233 (Id));
       W ("Has_Pragma_Unreferenced",         Flag180 (Id));
       W ("Has_Pragma_Unreferenced_Objects", Flag212 (Id));
+      W ("Has_Pragma_Unused",               Flag294 (Id));
       W ("Has_Predicates",                  Flag250 (Id));
       W ("Has_Primitive_Operations",        Flag120 (Id));
       W ("Has_Private_Ancestor",            Flag151 (Id));
diff --git a/gcc/ada/einfo.ads b/gcc/ada/einfo.ads
index 683c281..3a2d382 100644
--- a/gcc/ada/einfo.ads
+++ b/gcc/ada/einfo.ads
@@ -1902,12 +1902,19 @@ package Einfo is
 --       that clients should generally not test this flag directly, but instead
 --       use function Has_Unreferenced.
 
+--  ??? this real description was clobbered
+
 --    Has_Pragma_Unreferenced_Objects (Flag212)
---       Defined in type and subtype entities. Set if a valid pragma
---       Unreferenced_Objects applies to the type, indicating that no warning
---       should be given for objects of such a type for being unreferenced
---       (but unlike the case with pragma Unreferenced, it is ok to reference
---       such an object and no warning is generated.
+--       Defined in all entities. Set if a valid pragma Unused applies to an
+--       entity, indicating that warnings should be given if the entity is
+--       modified or referenced. This pragma is equivalent to a pair of
+--       Unmodified and Unreferenced pragmas.
+
+--    Has_Pragma_Unused (Flag294)
+--       Defined in all entries. Set if a valid pragma Unused applies to a
+--       variable or entity, indicating that warnings should not be given if
+--       it is never modified or referenced. Note: This pragma is exactly
+--       equivalent Unmodified and Unreference combined.
 
 --    Has_Predicates (Flag250)
 --       Defined in type and subtype entities. Set if a pragma Predicate or
@@ -5397,6 +5404,7 @@ package Einfo is
    --    Has_Pragma_Thread_Local_Storage     (Flag169)
    --    Has_Pragma_Unmodified               (Flag233)
    --    Has_Pragma_Unreferenced             (Flag180)
+   --    Has_Pragma_Unused                   (Flag294)
    --    Has_Private_Declaration             (Flag155)
    --    Has_Qualified_Name                  (Flag161)
    --    Has_Stream_Size_Clause              (Flag184)
@@ -6976,6 +6984,7 @@ package Einfo is
    function Has_Pragma_Unmodified               (Id : E) return B;
    function Has_Pragma_Unreferenced             (Id : E) return B;
    function Has_Pragma_Unreferenced_Objects     (Id : E) return B;
+   function Has_Pragma_Unused                   (Id : E) return B;
    function Has_Predicates                      (Id : E) return B;
    function Has_Primitive_Operations            (Id : E) return B;
    function Has_Private_Ancestor                (Id : E) return B;
@@ -7649,6 +7658,7 @@ package Einfo is
    procedure Set_Has_Pragma_Unmodified           (Id : E; V : B := True);
    procedure Set_Has_Pragma_Unreferenced         (Id : E; V : B := True);
    procedure Set_Has_Pragma_Unreferenced_Objects (Id : E; V : B := True);
+   procedure Set_Has_Pragma_Unused               (Id : E; V : B := True);
    procedure Set_Has_Predicates                  (Id : E; V : B := True);
    procedure Set_Has_Primitive_Operations        (Id : E; V : B := True);
    procedure Set_Has_Private_Ancestor            (Id : E; V : B := True);
@@ -8439,6 +8449,7 @@ package Einfo is
    pragma Inline (Has_Pragma_Unmodified);
    pragma Inline (Has_Pragma_Unreferenced);
    pragma Inline (Has_Pragma_Unreferenced_Objects);
+   pragma Inline (Has_Pragma_Unused);
    pragma Inline (Has_Predicates);
    pragma Inline (Has_Primitive_Operations);
    pragma Inline (Has_Private_Ancestor);
diff --git a/gcc/ada/lib-xref.adb b/gcc/ada/lib-xref.adb
index bff6d25..b1d5978 100644
--- a/gcc/ada/lib-xref.adb
+++ b/gcc/ada/lib-xref.adb
@@ -841,6 +841,8 @@ package body Lib.Xref is
 
          --  Check for pragma Unreferenced given and reference is within
          --  this source unit (occasion for possible warning to be issued).
+         --  Note that the entity may be marked as unreferenced by pragma
+         --  Unused.
 
          if Has_Unreferenced (E)
            and then In_Same_Extended_Unit (E, N)
@@ -875,8 +877,13 @@ package body Lib.Xref is
                   BE := First_Entity (Current_Scope);
                   while Present (BE) loop
                      if Chars (BE) = Chars (E) then
-                        Error_Msg_NE -- CODEFIX
-                          ("??pragma Unreferenced given for&!", N, BE);
+                        if Has_Pragma_Unused (E) then
+                           Error_Msg_NE -- CODEFIX
+                             ("??pragma Unused given for&!", N, BE);
+                        else
+                           Error_Msg_NE -- CODEFIX
+                             ("??pragma Unreferenced given for&!", N, BE);
+                        end if;
                         exit;
                      end if;
 
@@ -886,6 +893,9 @@ package body Lib.Xref is
 
             --  Here we issue the warning, since this is a real reference
 
+            elsif Has_Pragma_Unused (E) then
+               Error_Msg_NE -- CODEFIX
+                 ("??pragma Unused given for&!", N, E);
             else
                Error_Msg_NE -- CODEFIX
                  ("??pragma Unreferenced given for&!", N, E);
diff --git a/gcc/ada/par-prag.adb b/gcc/ada/par-prag.adb
index 5629914..900d96a 100644
--- a/gcc/ada/par-prag.adb
+++ b/gcc/ada/par-prag.adb
@@ -1487,6 +1487,7 @@ begin
            Pragma_Unreferenced_Objects           |
            Pragma_Unreserve_All_Interrupts       |
            Pragma_Unsuppress                     |
+           Pragma_Unused                         |
            Pragma_Use_VADS_Size                  |
            Pragma_Volatile                       |
            Pragma_Volatile_Components            |
diff --git a/gcc/ada/sem_prag.adb b/gcc/ada/sem_prag.adb
index 90d00fc..999ae35 100644
--- a/gcc/ada/sem_prag.adb
+++ b/gcc/ada/sem_prag.adb
@@ -3502,6 +3502,16 @@ package body Sem_Prag is
       --  related subprogram. Body_Id is the entity of the subprogram body.
       --  Flag Legal is set when the pragma is legal.
 
+      procedure Analyze_Unmodified_Or_Unused (Is_Unused : Boolean := False);
+      --  Perform full analysis of pragma Unmodified and the write aspect of
+      --  pragma Unused. Flag Is_Unused should be set when verifying the
+      --  semantics of pragma Unused.
+
+      procedure Analyze_Unreferenced_Or_Unused (Is_Unused : Boolean := False);
+      --  Perform full analysis of pragma Unreferenced and the read aspect of
+      --  pragma Unused. Flag Is_Unused should be set when verifying the
+      --  semantics of pragma Unused.
+
       procedure Check_Ada_83_Warning;
       --  Issues a warning message for the current pragma if operating in Ada
       --  83 mode (used for language pragmas that are not a standard part of
@@ -4465,6 +4475,274 @@ package body Sem_Prag is
          end if;
       end Analyze_Refined_Depends_Global_Post;
 
+      ----------------------------------
+      -- Analyze_Unmodified_Or_Unused --
+      ----------------------------------
+
+      procedure Analyze_Unmodified_Or_Unused (Is_Unused : Boolean := False) is
+         Arg      : Node_Id;
+         Arg_Expr : Node_Id;
+         Arg_Id   : Entity_Id;
+
+         Ghost_Error_Posted : Boolean := False;
+         --  Flag set when an error concerning the illegal mix of Ghost and
+         --  non-Ghost variables is emitted.
+
+         Ghost_Id : Entity_Id := Empty;
+         --  The entity of the first Ghost variable encountered while
+         --  processing the arguments of the pragma.
+
+      begin
+         GNAT_Pragma;
+         Check_At_Least_N_Arguments (1);
+
+         --  Loop through arguments
+
+         Arg := Arg1;
+         while Present (Arg) loop
+            Check_No_Identifier (Arg);
+
+            --  Note: the analyze call done by Check_Arg_Is_Local_Name will
+            --  in fact generate reference, so that the entity will have a
+            --  reference, which will inhibit any warnings about it not
+            --  being referenced, and also properly show up in the ali file
+            --  as a reference. But this reference is recorded before the
+            --  Has_Pragma_Unreferenced flag is set, so that no warning is
+            --  generated for this reference.
+
+            Check_Arg_Is_Local_Name (Arg);
+            Arg_Expr := Get_Pragma_Arg (Arg);
+
+            if Is_Entity_Name (Arg_Expr) then
+               Arg_Id := Entity (Arg_Expr);
+
+               --  Skip processing the argument if already flagged
+
+               if Is_Assignable (Arg_Id)
+                 and then not Has_Pragma_Unmodified (Arg_Id)
+                 and then not Has_Pragma_Unused (Arg_Id)
+               then
+                  Set_Has_Pragma_Unmodified (Arg_Id);
+
+                  if Is_Unused then
+                     Set_Has_Pragma_Unused (Arg_Id);
+                  end if;
+
+                  --  A pragma that applies to a Ghost entity becomes Ghost for
+                  --  the purposes of legality checks and removal of ignored
+                  --  Ghost code.
+
+                  Mark_Pragma_As_Ghost (N, Arg_Id);
+
+                  --  Capture the entity of the first Ghost variable being
+                  --  processed for error detection purposes.
+
+                  if Is_Ghost_Entity (Arg_Id) then
+                     if No (Ghost_Id) then
+                        Ghost_Id := Arg_Id;
+                     end if;
+
+                  --  Otherwise the variable is non-Ghost. It is illegal to mix
+                  --  references to Ghost and non-Ghost entities
+                  --  (SPARK RM 6.9).
+
+                  elsif Present (Ghost_Id)
+                    and then not Ghost_Error_Posted
+                  then
+                     Ghost_Error_Posted := True;
+
+                     Error_Msg_Name_1 := Pname;
+                     Error_Msg_N
+                       ("pragma % cannot mention ghost and non-ghost "
+                        & "variables", N);
+
+                     Error_Msg_Sloc := Sloc (Ghost_Id);
+                     Error_Msg_NE ("\& # declared as ghost", N, Ghost_Id);
+
+                     Error_Msg_Sloc := Sloc (Arg_Id);
+                     Error_Msg_NE ("\& # declared as non-ghost", N, Arg_Id);
+                  end if;
+
+               --  Warn if already flagged as Unused or Unmodified
+
+               elsif Has_Pragma_Unmodified (Arg_Id) then
+                  if Has_Pragma_Unused (Arg_Id) then
+                     Error_Msg_NE
+                       ("??pragma Unused given for &!", Arg_Expr, Arg_Id);
+                  else
+                     Error_Msg_NE
+                       ("??pragma Unmodified given for &!", Arg_Expr, Arg_Id);
+                  end if;
+
+               --  Otherwise the pragma referenced an illegal entity
+
+               else
+                  Error_Pragma_Arg
+                    ("pragma% can only be applied to a variable", Arg_Expr);
+               end if;
+            end if;
+
+            Next (Arg);
+         end loop;
+      end Analyze_Unmodified_Or_Unused;
+
+      -----------------------------------
+      -- Analyze_Unreference_Or_Unused --
+      -----------------------------------
+
+      procedure Analyze_Unreferenced_Or_Unused
+        (Is_Unused : Boolean := False)
+      is
+         Arg      : Node_Id;
+         Arg_Expr : Node_Id;
+         Arg_Id   : Entity_Id;
+         Citem    : Node_Id;
+
+         Ghost_Error_Posted : Boolean := False;
+         --  Flag set when an error concerning the illegal mix of Ghost and
+         --  non-Ghost names is emitted.
+
+         Ghost_Id : Entity_Id := Empty;
+         --  The entity of the first Ghost name encountered while processing
+         --  the arguments of the pragma.
+
+      begin
+         GNAT_Pragma;
+         Check_At_Least_N_Arguments (1);
+
+         --  Check case of appearing within context clause
+
+         if not Is_Unused and then Is_In_Context_Clause then
+
+            --  The arguments must all be units mentioned in a with clause in
+            --  the same context clause. Note that Par.Prag already checked
+            --  that the arguments are either identifiers or selected
+            --  components.
+
+            Arg := Arg1;
+            while Present (Arg) loop
+               Citem := First (List_Containing (N));
+               while Citem /= N loop
+                  Arg_Expr := Get_Pragma_Arg (Arg);
+
+                  if Nkind (Citem) = N_With_Clause
+                    and then Same_Name (Name (Citem), Arg_Expr)
+                  then
+                     Set_Has_Pragma_Unreferenced
+                       (Cunit_Entity
+                         (Get_Source_Unit
+                           (Library_Unit (Citem))));
+                     Set_Elab_Unit_Name (Arg_Expr, Name (Citem));
+                     exit;
+                  end if;
+
+                  Next (Citem);
+               end loop;
+
+               if Citem = N then
+                  Error_Pragma_Arg
+                    ("argument of pragma% is not withed unit", Arg);
+               end if;
+
+               Next (Arg);
+            end loop;
+
+         --  Case of not in list of context items
+
+         else
+            Arg := Arg1;
+            while Present (Arg) loop
+               Check_No_Identifier (Arg);
+
+               --  Note: the analyze call done by Check_Arg_Is_Local_Name will
+               --  in fact generate reference, so that the entity will have a
+               --  reference, which will inhibit any warnings about it not
+               --  being referenced, and also properly show up in the ali file
+               --  as a reference. But this reference is recorded before the
+               --  Has_Pragma_Unreferenced flag is set, so that no warning is
+               --  generated for this reference.
+
+               Check_Arg_Is_Local_Name (Arg);
+               Arg_Expr := Get_Pragma_Arg (Arg);
+
+               if Is_Entity_Name (Arg_Expr) then
+                  Arg_Id := Entity (Arg_Expr);
+
+                  --  Warn if already flagged as Unused or Unreferenced and
+                  --  skip processing the argument.
+
+                  if Has_Pragma_Unreferenced (Arg_Id) then
+                     if Has_Pragma_Unused (Arg_Id) then
+                        Error_Msg_NE
+                          ("??pragma Unused given for &!", Arg_Expr, Arg_Id);
+                     else
+                        Error_Msg_NE
+                          ("??pragma Unreferenced given for &!", Arg_Expr,
+                           Arg_Id);
+                     end if;
+
+                  --  Apply Unreferenced to the entity
+
+                  else
+                     --  If the entity is overloaded, the pragma applies to the
+                     --  most recent overloading, as documented. In this case,
+                     --  name resolution does not generate a reference, so it
+                     --  must be done here explicitly.
+
+                     if Is_Overloaded (Arg_Expr) then
+                        Generate_Reference (Arg_Id, N);
+                     end if;
+
+                     Set_Has_Pragma_Unreferenced (Arg_Id);
+
+                     if Is_Unused then
+                        Set_Has_Pragma_Unused (Arg_Id);
+                     end if;
+
+                     --  A pragma that applies to a Ghost entity becomes Ghost
+                     --  for the purposes of legality checks and removal of
+                     --  ignored Ghost code.
+
+                     Mark_Pragma_As_Ghost (N, Arg_Id);
+
+                     --  Capture the entity of the first Ghost name being
+                     --  processed for error detection purposes.
+
+                     if Is_Ghost_Entity (Arg_Id) then
+                        if No (Ghost_Id) then
+                           Ghost_Id := Arg_Id;
+                        end if;
+
+                     --  Otherwise the name is non-Ghost. It is illegal to mix
+                     --  references to Ghost and non-Ghost entities
+                     --  (SPARK RM 6.9).
+
+                     elsif Present (Ghost_Id)
+                       and then not Ghost_Error_Posted
+                     then
+                        Ghost_Error_Posted := True;
+
+                        Error_Msg_Name_1 := Pname;
+                        Error_Msg_N
+                          ("pragma % cannot mention ghost and non-ghost "
+                           & "names", N);
+
+                        Error_Msg_Sloc := Sloc (Ghost_Id);
+                        Error_Msg_NE
+                          ("\& # declared as ghost", N, Ghost_Id);
+
+                        Error_Msg_Sloc := Sloc (Arg_Id);
+                        Error_Msg_NE
+                          ("\& # declared as non-ghost", N, Arg_Id);
+                     end if;
+                  end if;
+               end if;
+
+               Next (Arg);
+            end loop;
+         end if;
+      end Analyze_Unreferenced_Or_Unused;
+
       --------------------------
       -- Check_Ada_83_Warning --
       --------------------------
@@ -22270,6 +22548,30 @@ package body Sem_Prag is
             Set_Is_Unchecked_Union  (Base_Type (Typ));
          end Unchecked_Union;
 
+         ----------------------------
+         -- Unevaluated_Use_Of_Old --
+         ----------------------------
+
+         --  pragma Unevaluated_Use_Of_Old (Error | Warn | Allow);
+
+         when Pragma_Unevaluated_Use_Of_Old =>
+            GNAT_Pragma;
+            Check_Arg_Count (1);
+            Check_No_Identifiers;
+            Check_Arg_Is_One_Of (Arg1, Name_Error, Name_Warn, Name_Allow);
+
+            --  Suppress/Unsuppress can appear as a configuration pragma, or in
+            --  a declarative part or a package spec.
+
+            if not Is_Configuration_Pragma then
+               Check_Is_In_Decl_Part_Or_Package_Spec;
+            end if;
+
+            --  Store proper setting of Uneval_Old
+
+            Get_Name_String (Chars (Get_Pragma_Arg (Arg1)));
+            Uneval_Old := Fold_Upper (Name_Buffer (1));
+
          ------------------------
          -- Unimplemented_Unit --
          ------------------------
@@ -22281,10 +22583,9 @@ package body Sem_Prag is
          --  body, not in the spec).
 
          when Pragma_Unimplemented_Unit => Unimplemented_Unit : declare
-            Cunitent : constant Entity_Id :=
+            Cunitent : constant Entity_Id   :=
                          Cunit_Entity (Get_Source_Unit (Loc));
-            Ent_Kind : constant Entity_Kind :=
-                         Ekind (Cunitent);
+            Ent_Kind : constant Entity_Kind := Ekind (Cunitent);
 
          begin
             GNAT_Pragma;
@@ -22350,92 +22651,8 @@ package body Sem_Prag is
 
          --  pragma Unmodified (LOCAL_NAME {, LOCAL_NAME});
 
-         when Pragma_Unmodified => Unmodified : declare
-            Arg      : Node_Id;
-            Arg_Expr : Node_Id;
-            Arg_Id   : Entity_Id;
-
-            Ghost_Error_Posted : Boolean := False;
-            --  Flag set when an error concerning the illegal mix of Ghost and
-            --  non-Ghost variables is emitted.
-
-            Ghost_Id : Entity_Id := Empty;
-            --  The entity of the first Ghost variable encountered while
-            --  processing the arguments of the pragma.
-
-         begin
-            GNAT_Pragma;
-            Check_At_Least_N_Arguments (1);
-
-            --  Loop through arguments
-
-            Arg := Arg1;
-            while Present (Arg) loop
-               Check_No_Identifier (Arg);
-
-               --  Note: the analyze call done by Check_Arg_Is_Local_Name will
-               --  in fact generate reference, so that the entity will have a
-               --  reference, which will inhibit any warnings about it not
-               --  being referenced, and also properly show up in the ali file
-               --  as a reference. But this reference is recorded before the
-               --  Has_Pragma_Unreferenced flag is set, so that no warning is
-               --  generated for this reference.
-
-               Check_Arg_Is_Local_Name (Arg);
-               Arg_Expr := Get_Pragma_Arg (Arg);
-
-               if Is_Entity_Name (Arg_Expr) then
-                  Arg_Id := Entity (Arg_Expr);
-
-                  if Is_Assignable (Arg_Id) then
-                     Set_Has_Pragma_Unmodified (Arg_Id);
-
-                     --  A pragma that applies to a Ghost entity becomes Ghost
-                     --  for the purposes of legality checks and removal of
-                     --  ignored Ghost code.
-
-                     Mark_Pragma_As_Ghost (N, Arg_Id);
-
-                     --  Capture the entity of the first Ghost variable being
-                     --  processed for error detection purposes.
-
-                     if Is_Ghost_Entity (Arg_Id) then
-                        if No (Ghost_Id) then
-                           Ghost_Id := Arg_Id;
-                        end if;
-
-                     --  Otherwise the variable is non-Ghost. It is illegal
-                     --  to mix references to Ghost and non-Ghost entities
-                     --  (SPARK RM 6.9).
-
-                     elsif Present (Ghost_Id)
-                       and then not Ghost_Error_Posted
-                     then
-                        Ghost_Error_Posted := True;
-
-                        Error_Msg_Name_1 := Pname;
-                        Error_Msg_N
-                          ("pragma % cannot mention ghost and non-ghost "
-                           & "variables", N);
-
-                        Error_Msg_Sloc := Sloc (Ghost_Id);
-                        Error_Msg_NE ("\& # declared as ghost", N, Ghost_Id);
-
-                        Error_Msg_Sloc := Sloc (Arg_Id);
-                        Error_Msg_NE ("\& # declared as non-ghost", N, Arg_Id);
-                     end if;
-
-                  --  Otherwise the pragma referenced an illegal entity
-
-                  else
-                     Error_Pragma_Arg
-                       ("pragma% can only be applied to a variable", Arg_Expr);
-                  end if;
-               end if;
-
-               Next (Arg);
-            end loop;
-         end Unmodified;
+         when Pragma_Unmodified =>
+            Analyze_Unmodified_Or_Unused;
 
          ------------------
          -- Unreferenced --
@@ -22447,133 +22664,8 @@ package body Sem_Prag is
 
          --  pragma Unreferenced (library_unit_NAME {, library_unit_NAME}
 
-         when Pragma_Unreferenced => Unreferenced : declare
-            Arg      : Node_Id;
-            Arg_Expr : Node_Id;
-            Arg_Id   : Entity_Id;
-            Citem    : Node_Id;
-
-            Ghost_Error_Posted : Boolean := False;
-            --  Flag set when an error concerning the illegal mix of Ghost and
-            --  non-Ghost names is emitted.
-
-            Ghost_Id : Entity_Id := Empty;
-            --  The entity of the first Ghost name encountered while processing
-            --  the arguments of the pragma.
-
-         begin
-            GNAT_Pragma;
-            Check_At_Least_N_Arguments (1);
-
-            --  Check case of appearing within context clause
-
-            if Is_In_Context_Clause then
-
-               --  The arguments must all be units mentioned in a with clause
-               --  in the same context clause. Note we already checked (in
-               --  Par.Prag) that the arguments are either identifiers or
-               --  selected components.
-
-               Arg := Arg1;
-               while Present (Arg) loop
-                  Citem := First (List_Containing (N));
-                  while Citem /= N loop
-                     Arg_Expr := Get_Pragma_Arg (Arg);
-
-                     if Nkind (Citem) = N_With_Clause
-                       and then Same_Name (Name (Citem), Arg_Expr)
-                     then
-                        Set_Has_Pragma_Unreferenced
-                          (Cunit_Entity
-                             (Get_Source_Unit
-                                (Library_Unit (Citem))));
-                        Set_Elab_Unit_Name (Arg_Expr, Name (Citem));
-                        exit;
-                     end if;
-
-                     Next (Citem);
-                  end loop;
-
-                  if Citem = N then
-                     Error_Pragma_Arg
-                       ("argument of pragma% is not withed unit", Arg);
-                  end if;
-
-                  Next (Arg);
-               end loop;
-
-            --  Case of not in list of context items
-
-            else
-               Arg := Arg1;
-               while Present (Arg) loop
-                  Check_No_Identifier (Arg);
-
-                  --  Note: the analyze call done by Check_Arg_Is_Local_Name
-                  --  will in fact generate reference, so that the entity will
-                  --  have a reference, which will inhibit any warnings about
-                  --  it not being referenced, and also properly show up in the
-                  --  ali file as a reference. But this reference is recorded
-                  --  before the Has_Pragma_Unreferenced flag is set, so that
-                  --  no warning is generated for this reference.
-
-                  Check_Arg_Is_Local_Name (Arg);
-                  Arg_Expr := Get_Pragma_Arg (Arg);
-
-                  if Is_Entity_Name (Arg_Expr) then
-                     Arg_Id := Entity (Arg_Expr);
-
-                     --  If the entity is overloaded, the pragma applies to the
-                     --  most recent overloading, as documented. In this case,
-                     --  name resolution does not generate a reference, so it
-                     --  must be done here explicitly.
-
-                     if Is_Overloaded (Arg_Expr) then
-                        Generate_Reference (Arg_Id, N);
-                     end if;
-
-                     Set_Has_Pragma_Unreferenced (Arg_Id);
-
-                     --  A pragma that applies to a Ghost entity becomes Ghost
-                     --  for the purposes of legality checks and removal of
-                     --  ignored Ghost code.
-
-                     Mark_Pragma_As_Ghost (N, Arg_Id);
-
-                     --  Capture the entity of the first Ghost name being
-                     --  processed for error detection purposes.
-
-                     if Is_Ghost_Entity (Arg_Id) then
-                        if No (Ghost_Id) then
-                           Ghost_Id := Arg_Id;
-                        end if;
-
-                     --  Otherwise the name is non-Ghost. It is illegal to mix
-                     --  references to Ghost and non-Ghost entities
-                     --  (SPARK RM 6.9).
-
-                     elsif Present (Ghost_Id)
-                       and then not Ghost_Error_Posted
-                     then
-                        Ghost_Error_Posted := True;
-
-                        Error_Msg_Name_1 := Pname;
-                        Error_Msg_N
-                          ("pragma % cannot mention ghost and non-ghost names",
-                           N);
-
-                        Error_Msg_Sloc := Sloc (Ghost_Id);
-                        Error_Msg_NE ("\& # declared as ghost", N, Ghost_Id);
-
-                        Error_Msg_Sloc := Sloc (Arg_Id);
-                        Error_Msg_NE ("\& # declared as non-ghost", N, Arg_Id);
-                     end if;
-                  end if;
-
-                  Next (Arg);
-               end loop;
-            end if;
-         end Unreferenced;
+         when Pragma_Unreferenced =>
+            Analyze_Unreferenced_Or_Unused;
 
          --------------------------
          -- Unreferenced_Objects --
@@ -22681,29 +22773,15 @@ package body Sem_Prag is
             Ada_2005_Pragma;
             Process_Suppress_Unsuppress (Suppress_Case => False);
 
-         ----------------------------
-         -- Unevaluated_Use_Of_Old --
-         ----------------------------
-
-         --  pragma Unevaluated_Use_Of_Old (Error | Warn | Allow);
-
-         when Pragma_Unevaluated_Use_Of_Old =>
-            GNAT_Pragma;
-            Check_Arg_Count (1);
-            Check_No_Identifiers;
-            Check_Arg_Is_One_Of (Arg1, Name_Error, Name_Warn, Name_Allow);
-
-            --  Suppress/Unsuppress can appear as a configuration pragma, or in
-            --  a declarative part or a package spec.
-
-            if not Is_Configuration_Pragma then
-               Check_Is_In_Decl_Part_Or_Package_Spec;
-            end if;
+         ------------
+         -- Unused --
+         ------------
 
-            --  Store proper setting of Uneval_Old
+         --  pragma Unused (LOCAL_NAME {, LOCAL_NAME});
 
-            Get_Name_String (Chars (Get_Pragma_Arg (Arg1)));
-            Uneval_Old := Fold_Upper (Name_Buffer (1));
+         when Pragma_Unused =>
+            Analyze_Unmodified_Or_Unused   (Is_Unused => True);
+            Analyze_Unreferenced_Or_Unused (Is_Unused => True);
 
          -------------------
          -- Use_VADS_Size --
@@ -26386,8 +26464,8 @@ package body Sem_Prag is
                then
                   Error_Msg_N
                     ("cannot modify inherited condition (SPARK RM 6.1.1(1))",
-                      Parent (Subp));
-                  Error_Msg_Sloc := Sloc (New_E);
+                     Parent (Subp));
+                  Error_Msg_Sloc   := Sloc (New_E);
                   Error_Msg_Node_2 := Subp;
                   Error_Msg_NE
                     ("\overriding of&# forces overriding of&",
@@ -28378,6 +28456,7 @@ package body Sem_Prag is
       Pragma_Type_Invariant                 => -1,
       Pragma_Type_Invariant_Class           => -1,
       Pragma_Unchecked_Union                =>  0,
+      Pragma_Unevaluated_Use_Of_Old         =>  0,
       Pragma_Unimplemented_Unit             =>  0,
       Pragma_Universal_Aliasing             =>  0,
       Pragma_Universal_Data                 =>  0,
@@ -28386,7 +28465,7 @@ package body Sem_Prag is
       Pragma_Unreferenced_Objects           =>  0,
       Pragma_Unreserve_All_Interrupts       =>  0,
       Pragma_Unsuppress                     =>  0,
-      Pragma_Unevaluated_Use_Of_Old         =>  0,
+      Pragma_Unused                         =>  0,
       Pragma_Use_VADS_Size                  =>  0,
       Pragma_Validity_Checks                =>  0,
       Pragma_Volatile                       =>  0,
diff --git a/gcc/ada/sem_util.adb b/gcc/ada/sem_util.adb
index 0c4f9eb..94e97b4 100644
--- a/gcc/ada/sem_util.adb
+++ b/gcc/ada/sem_util.adb
@@ -17618,11 +17618,20 @@ package body Sem_Util is
                if Comes_From_Source (Exp)
                  or else Modification_Comes_From_Source
                then
-                  --  Give warning if pragma unmodified given and we are
+                  --  Give warning if pragma unmodified is given and we are
                   --  sure this is a modification.
 
                   if Has_Pragma_Unmodified (Ent) and then Sure then
-                     Error_Msg_NE ("??pragma Unmodified given for &!", N, Ent);
+
+                     --  Note that the entity may be present only as a result
+                     --  of pragma Unused.
+
+                     if Has_Pragma_Unused (Ent) then
+                        Error_Msg_NE ("??pragma Unused given for &!", N, Ent);
+                     else
+                        Error_Msg_NE
+                          ("??pragma Unmodified given for &!", N, Ent);
+                     end if;
                   end if;
 
                   Set_Never_Set_In_Source (Ent, False);
diff --git a/gcc/ada/snames.ads-tmpl b/gcc/ada/snames.ads-tmpl
index 76b353b..920b24e 100644
--- a/gcc/ada/snames.ads-tmpl
+++ b/gcc/ada/snames.ads-tmpl
@@ -653,6 +653,7 @@ package Snames is
    Name_Unreferenced                   : constant Name_Id := N + $; -- GNAT
    Name_Unreferenced_Objects           : constant Name_Id := N + $; -- GNAT
    Name_Unreserve_All_Interrupts       : constant Name_Id := N + $; -- GNAT
+   Name_Unused                         : constant Name_Id := N + $; -- GNAT
    Name_Volatile                       : constant Name_Id := N + $;
    Name_Volatile_Components            : constant Name_Id := N + $;
    Name_Volatile_Full_Access           : constant Name_Id := N + $; -- GNAT
@@ -1965,6 +1966,7 @@ package Snames is
       Pragma_Unreferenced,
       Pragma_Unreferenced_Objects,
       Pragma_Unreserve_All_Interrupts,
+      Pragma_Unused,
       Pragma_Volatile,
       Pragma_Volatile_Components,
       Pragma_Volatile_Full_Access,