atree.ads, atree.adb (New_Copy_Tree): If hash table is being used and itype is visited...

2007-08-14  Ed Schonberg  <schonberg@adacore.com>
	    Robert Dewar  <dewar@adacore.com>

	* atree.ads, atree.adb (New_Copy_Tree): If hash table is being used and
	itype is visited, make an entry into table to link associated node and
	new itype.
	Add comments and correct harmless error in Build_NCT_Hash_Tables
	(Array_Aggr_Subtype): Associate each itype created for an index type to
	the corresponding range construct, and not to the aggregate itself. to
	maintain a one-to-one correspondence between itype and its associated
	node, to prevent errors when complex expression is copied.
	Fix mishandling of multiple levels of parens

	* sem_aggr.adb: Create a limited view of an incomplete type, to make
	treatment of limited views uniform for all visible declarations in a
	limited_withed package.
	(New_Copy_Tree): If hash table is being used and itype is visited,
	make an entry into table to link associated node and new itype.
	(Resolve_Record_Aggregate): Do not add an others box association for a
	discriminated record component that has only discriminants, when there
	is a box association for the component itself.

	* par-ch4.adb: Fix mishandling of multiple levels of parens

From-SVN: r127412

gcc/ada/atree.ads

@@ -94,12 +94,11 @@ package Atree is
    --   Rewrite_Ins   A flag set if a node is marked as a rewrite inserted
    --                 node as a result of a call to Mark_Rewrite_Insertion.
 
-   --   Paren_Count   A 2-bit count used on expression nodes to indicate
-   --                 the level of parentheses. Up to 3 levels can be
-   --                 accomodated. Anything more than 3 levels is treated
-   --                 as 3 levels (conformance tests that complain about
-   --                 this are hereby deemed pathological!). Set to zero
-   --                 for non-subexpression nodes.
+   --   Paren_Count   A 2-bit count used in sub-expression nodes to indicate
+   --                 the level of parentheses. The settings are 0,1,2 and
+   --                 3 for many. If the value is 3, then an auxiliary table
+   --                 is used to indicate the real value. Set to zero for
+   --                 non-subexpression nodes.
 
    --   Comes_From_Source
    --                 This flag is present in all nodes. It is set if the
@@ -203,10 +202,6 @@ package Atree is
    --   Elist7-Elist28, Uint7-Uint28, Ureal7-Ureal28). Note that not all
    --   these functions are defined, only the ones that are actually used.
 
-   type Paren_Count_Type is mod 4;
-   for Paren_Count_Type'Size use 2;
-   --  Type used for Paren_Count field
-
    function Last_Node_Id return Node_Id;
    pragma Inline (Last_Node_Id);
    --  Returns Id of last allocated node Id
@@ -548,7 +543,7 @@ package Atree is
 
    --  The result returned by Traverse is Abandon if processing was terminated
    --  by a call to Process returning Abandon, otherwise it is OK (meaning that
-   --  all calls to process returned either OK or Skip).
+   --  all calls to process returned either OK, OK_Orig, or Skip).
 
    generic
      with function Process (N : Node_Id) return Traverse_Result is <>;
@@ -579,7 +574,7 @@ package Atree is
    function Sloc              (N : Node_Id) return Source_Ptr;
    pragma Inline (Sloc);
 
-   function Paren_Count       (N : Node_Id) return Paren_Count_Type;
+   function Paren_Count       (N : Node_Id) return Nat;
    pragma Inline (Paren_Count);
 
    function Parent            (N : Node_Id) return Node_Id;
@@ -623,7 +618,7 @@ package Atree is
    procedure Set_Sloc         (N : Node_Id; Val : Source_Ptr);
    pragma Inline (Set_Sloc);
 
-   procedure Set_Paren_Count  (N : Node_Id; Val : Paren_Count_Type);
+   procedure Set_Paren_Count  (N : Node_Id; Val : Nat);
    pragma Inline (Set_Paren_Count);
 
    procedure Set_Parent       (N : Node_Id; Val : Node_Id);

gcc/ada/par-ch4.adb

@@ -69,7 +69,7 @@ package body Ch4 is
 
    procedure Bad_Range_Attribute (Loc : Source_Ptr) is
    begin
-      Error_Msg ("range attribute cannot be used in expression", Loc);
+      Error_Msg ("range attribute cannot be used in expression!", Loc);
       Resync_Expression;
    end Bad_Range_Attribute;
 
@@ -1267,18 +1267,14 @@ package body Ch4 is
             then
                Error_Msg
                  ("|parentheses not allowed for range attribute", Lparen_Sloc);
+               Scan; -- past right paren
                return Expr_Node;
             end if;
 
-            --  Bump paren count of expression, note that if the paren count
-            --  is already at the maximum, then we leave it alone. This will
-            --  cause some failures in pathalogical conformance tests, which
-            --  we do not shed a tear over!
+            --  Bump paren count of expression
 
             if Expr_Node /= Error then
-               if Paren_Count (Expr_Node) /= Paren_Count_Type'Last then
-                  Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
-               end if;
+               Set_Paren_Count (Expr_Node, Paren_Count (Expr_Node) + 1);
             end if;
 
             T_Right_Paren; -- past right paren (error message if none)
@@ -1577,11 +1573,13 @@ package body Ch4 is
    --  called in all contexts where a right parenthesis cannot legitimately
    --  follow an expression.
 
-   --  Error recovery: can raise Error_Resync
+   --  Error recovery: can not raise Error_Resync
 
    function P_Expression_No_Right_Paren return Node_Id is
+      Expr : constant Node_Id := P_Expression;
    begin
-      return No_Right_Paren (P_Expression);
+      Check_No_Right_Paren;
+      return Expr;
    end P_Expression_No_Right_Paren;
 
    ----------------------------------------
@@ -1805,7 +1803,10 @@ package body Ch4 is
 
          else
             if Token = Tok_Double_Asterisk then
-               if Style_Check then Style.Check_Exponentiation_Operator; end if;
+               if Style_Check then
+                  Style.Check_Exponentiation_Operator;
+               end if;
+
                Node2 := New_Node (N_Op_Expon, Token_Ptr);
                Scan; -- past **
                Set_Left_Opnd (Node2, Node1);
@@ -1818,7 +1819,11 @@ package body Ch4 is
                exit when Token not in Token_Class_Mulop;
                Tokptr := Token_Ptr;
                Node2 := New_Node (P_Multiplying_Operator, Tokptr);
-               if Style_Check then Style.Check_Binary_Operator; end if;
+
+               if Style_Check then
+                  Style.Check_Binary_Operator;
+               end if;
+
                Scan; -- past operator
                Set_Left_Opnd (Node2, Node1);
                Set_Right_Opnd (Node2, P_Factor);
@@ -1830,7 +1835,11 @@ package body Ch4 is
                exit when Token not in Token_Class_Binary_Addop;
                Tokptr := Token_Ptr;
                Node2 := New_Node (P_Binary_Adding_Operator, Tokptr);
-               if Style_Check then Style.Check_Binary_Operator; end if;
+
+               if Style_Check then
+                  Style.Check_Binary_Operator;
+               end if;
+
                Scan; -- past operator
                Set_Left_Opnd (Node2, Node1);
                Set_Right_Opnd (Node2, P_Term);
@@ -1849,7 +1858,11 @@ package body Ch4 is
          if Token in Token_Class_Unary_Addop then
             Tokptr := Token_Ptr;
             Node1 := New_Node (P_Unary_Adding_Operator, Tokptr);
-            if Style_Check then Style.Check_Unary_Plus_Or_Minus; end if;
+
+            if Style_Check then
+               Style.Check_Unary_Plus_Or_Minus;
+            end if;
+
             Scan; -- past operator
             Set_Right_Opnd (Node1, P_Term);
             Set_Op_Name (Node1);
@@ -1951,6 +1964,39 @@ package body Ch4 is
       Attr_Node : Node_Id;
 
    begin
+      --  We don't just want to roar ahead and call P_Simple_Expression
+      --  here, since we want to handle the case of a parenthesized range
+      --  attribute cleanly.
+
+      if Token = Tok_Left_Paren then
+         declare
+            Lptr       : constant Source_Ptr := Token_Ptr;
+            Scan_State : Saved_Scan_State;
+
+         begin
+            Save_Scan_State (Scan_State);
+            Scan; -- past left paren
+            Sexpr := P_Simple_Expression;
+
+            if Token = Tok_Apostrophe then
+               Attr_Node := P_Range_Attribute_Reference (Sexpr);
+               Expr_Form := EF_Range_Attr;
+
+               if Token = Tok_Right_Paren then
+                  Scan; -- scan past right paren if present
+               end if;
+
+               Error_Msg ("parentheses not allowed for range attribute", Lptr);
+
+               return Attr_Node;
+            end if;
+
+            Restore_Scan_State (Scan_State);
+         end;
+      end if;
+
+      --  Here after dealing with parenthesized range attribute
+
       Sexpr := P_Simple_Expression;
 
       if Token = Tok_Apostrophe then
@@ -2007,7 +2053,11 @@ package body Ch4 is
    begin
       if Token = Tok_Abs then
          Node1 := New_Node (N_Op_Abs, Token_Ptr);
-         if Style_Check then Style.Check_Abs_Not; end if;
+
+         if Style_Check then
+            Style.Check_Abs_Not;
+         end if;
+
          Scan; -- past ABS
          Set_Right_Opnd (Node1, P_Primary);
          Set_Op_Name (Node1);
@@ -2015,7 +2065,11 @@ package body Ch4 is
 
       elsif Token = Tok_Not then
          Node1 := New_Node (N_Op_Not, Token_Ptr);
-         if Style_Check then Style.Check_Abs_Not; end if;
+
+         if Style_Check then
+            Style.Check_Abs_Not;
+         end if;
+
          Scan; -- past NOT
          Set_Right_Opnd (Node1, P_Primary);
          Set_Op_Name (Node1);
@@ -2116,7 +2170,18 @@ package body Ch4 is
             --  Left paren, starts aggregate or parenthesized expression
 
             when Tok_Left_Paren =>
-               return P_Aggregate_Or_Paren_Expr;
+               declare
+                  Expr : constant Node_Id := P_Aggregate_Or_Paren_Expr;
+
+               begin
+                  if Nkind (Expr) = N_Attribute_Reference
+                    and then Attribute_Name (Expr) = Name_Range
+                  then
+                     Bad_Range_Attribute (Sloc (Expr));
+                  end if;
+
+                  return Expr;
+               end;
 
             --  Allocator
 
@@ -2174,7 +2239,10 @@ package body Ch4 is
    function P_Logical_Operator return Node_Kind is
    begin
       if Token = Tok_And then
-         if Style_Check then Style.Check_Binary_Operator; end if;
+         if Style_Check then
+            Style.Check_Binary_Operator;
+         end if;
+
          Scan; -- past AND
 
          if Token = Tok_Then then
@@ -2185,7 +2253,10 @@ package body Ch4 is
          end if;
 
       elsif Token = Tok_Or then
-         if Style_Check then Style.Check_Binary_Operator; end if;
+         if Style_Check then
+            Style.Check_Binary_Operator;
+         end if;
+
          Scan; -- past OR
 
          if Token = Tok_Else then
@@ -2196,7 +2267,10 @@ package body Ch4 is
          end if;
 
       else -- Token = Tok_Xor
-         if Style_Check then Style.Check_Binary_Operator; end if;
+         if Style_Check then
+            Style.Check_Binary_Operator;
+         end if;
+
          Scan; -- past XOR
          return N_Op_Xor;
       end if;
@@ -2235,7 +2309,11 @@ package body Ch4 is
       end if;
 
       Op_Kind := Relop_Node (Token);
-      if Style_Check then Style.Check_Binary_Operator; end if;
+
+      if Style_Check then
+         Style.Check_Binary_Operator;
+      end if;
+
       Scan; -- past operator token
 
       if Prev_Token = Tok_Not then

gcc/ada/sem_aggr.adb

@@ -39,11 +39,9 @@ with Namet;    use Namet;
 with Nmake;    use Nmake;
 with Nlists;   use Nlists;
 with Opt;      use Opt;
-with Rtsfind;  use Rtsfind;
 with Sem;      use Sem;
 with Sem_Cat;  use Sem_Cat;
 with Sem_Ch3;  use Sem_Ch3;
-with Sem_Ch8;  use Sem_Ch8;
 with Sem_Ch13; use Sem_Ch13;
 with Sem_Eval; use Sem_Eval;
 with Sem_Res;  use Sem_Res;
@@ -88,7 +86,7 @@ package body Sem_Aggr is
    --  E_Component/E_Discriminant entity in the record case, in which case the
    --  type of the component will be used for the test. If Typ is any other
    --  kind of entity, the call is ignored. Expr is the component node in the
-   --  aggregate which is an explicit occurrence of NULL. An error will be
+   --  aggregate which is known to have a null value. A warning message will be
    --  issued if the component is null excluding.
    --
    --  It would be better to pass the proper type for Typ ???
@@ -639,9 +637,11 @@ package body Sem_Aggr is
             Index_Typ  : Entity_Id;
 
          begin
-            --  Construct the Index subtype
+            --  Construct the Index subtype, and associate it with the range
+            --  construct that generates it.
 
-            Index_Typ := Create_Itype (Subtype_Kind (Ekind (Index_Base)), N);
+            Index_Typ :=
+              Create_Itype (Subtype_Kind (Ekind (Index_Base)), Aggr_Range (J));
 
             Set_Etype (Index_Typ, Index_Base);
 
@@ -684,32 +684,15 @@ package body Sem_Aggr is
       Set_Is_Internal    (Itype, True);
       Init_Size_Align    (Itype);
 
-      --  Handle aggregate initializing statically allocated dispatch table
-
-      if Static_Dispatch_Tables
-        and then VM_Target = No_VM
-        and then RTU_Loaded (Ada_Tags)
-
-         --  Avoid circularity when rebuilding the compiler
-
-        and then Cunit_Entity (Get_Source_Unit (N)) /= RTU_Entity (Ada_Tags)
-        and then (Etype (N) = RTE (RE_Address_Array)
-                    or else
-                  Base_Type (Etype (N)) = RTE (RE_Tag_Table))
-      then
-         Set_Size_Known_At_Compile_Time (Itype);
-
       --  A simple optimization: purely positional aggregates of static
       --  components should be passed to gigi unexpanded whenever possible,
       --  and regardless of the staticness of the bounds themselves. Subse-
       --  quent checks in exp_aggr verify that type is not packed, etc.
 
-      else
-         Set_Size_Known_At_Compile_Time (Itype,
-            Is_Fully_Positional
-              and then Comes_From_Source (N)
-              and then Size_Known_At_Compile_Time (Component_Type (Typ)));
-      end if;
+      Set_Size_Known_At_Compile_Time (Itype,
+         Is_Fully_Positional
+           and then Comes_From_Source (N)
+           and then Size_Known_At_Compile_Time (Component_Type (Typ)));
 
       --  We always need a freeze node for a packed array subtype, so that
       --  we can build the Packed_Array_Type corresponding to the subtype.
@@ -1022,7 +1005,7 @@ package body Sem_Aggr is
                Pkind = N_Procedure_Call_Statement  or else
                Pkind = N_Generic_Association       or else
                Pkind = N_Formal_Object_Declaration or else
-               Pkind = N_Return_Statement          or else
+               Pkind = N_Simple_Return_Statement   or else
                Pkind = N_Object_Declaration        or else
                Pkind = N_Component_Declaration     or else
                Pkind = N_Parameter_Specification   or else
@@ -1719,7 +1702,7 @@ package body Sem_Aggr is
                --  Ada 2005 (AI-231)
 
                if Ada_Version >= Ada_05
-                 and then Nkind (Expression (Assoc)) = N_Null
+                 and then Known_Null (Expression (Assoc))
                then
                   Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
                end if;
@@ -1851,7 +1834,7 @@ package body Sem_Aggr is
             --  Ada 2005 (AI-231)
 
             if Ada_Version >= Ada_05
-              and then Nkind (Expr) = N_Null
+              and then Known_Null (Expr)
             then
                Check_Can_Never_Be_Null (Etype (N), Expr);
             end if;
@@ -1869,7 +1852,7 @@ package body Sem_Aggr is
             --  Ada 2005 (AI-231)
 
             if Ada_Version >= Ada_05
-              and then Nkind (Assoc) = N_Null
+              and then Known_Null (Assoc)
             then
                Check_Can_Never_Be_Null (Etype (N), Expression (Assoc));
             end if;
@@ -2401,7 +2384,7 @@ package body Sem_Aggr is
                      --  Ada 2005 (AI-231)
 
                      if Ada_Version >= Ada_05
-                       and then Nkind (Expression (Assoc)) = N_Null
+                       and then Known_Null (Expression (Assoc))
                      then
                         Check_Can_Never_Be_Null (Compon, Expression (Assoc));
                      end if;
@@ -2731,7 +2714,7 @@ package body Sem_Aggr is
                --  Ada 2005 (AI-231)
 
                if Ada_Version >= Ada_05
-                 and then Nkind (Positional_Expr) = N_Null
+                 and then Known_Null (Positional_Expr)
                then
                   Check_Can_Never_Be_Null (Discrim, Positional_Expr);
                end if;
@@ -2969,7 +2952,7 @@ package body Sem_Aggr is
          --  Ada 2005 (AI-231)
 
          if Ada_Version >= Ada_05
-           and then Nkind (Positional_Expr) = N_Null
+           and then Known_Null (Positional_Expr)
          then
             Check_Can_Never_Be_Null (Component, Positional_Expr);
          end if;
@@ -3052,7 +3035,7 @@ package body Sem_Aggr is
                   then
                      --  We build a partially initialized aggregate with the
                      --  values of the discriminants and box initialization
-                     --  for the rest.
+                     --  for the rest, if other components are present.
 
                      declare
                         Loc        : constant Source_Ptr := Sloc (N);
@@ -3085,13 +3068,29 @@ package body Sem_Aggr is
                            Next_Elmt (Discr_Elmt);
                         end loop;
 
-                        Append
-                          (Make_Component_Association (Loc,
-                             Choices     =>
-                               New_List (Make_Others_Choice (Loc)),
-                             Expression  => Empty,
-                             Box_Present => True),
-                           Component_Associations (Expr));
+                        declare
+                           Comp : Entity_Id;
+
+                        begin
+                           --  Look for a component that is not a discriminant
+                           --  before creating an others box association.
+
+                           Comp := First_Component (Ctyp);
+                           while Present (Comp) loop
+                              if Ekind (Comp) = E_Component then
+                                 Append
+                                   (Make_Component_Association (Loc,
+                                      Choices     =>
+                                        New_List (Make_Others_Choice (Loc)),
+                                      Expression  => Empty,
+                                      Box_Present => True),
+                                    Component_Associations (Expr));
+                                 exit;
+                              end if;
+
+                              Next_Component (Comp);
+                           end loop;
+                        end;
 
                         Add_Association
                           (Component      => Component,
@@ -3271,7 +3270,7 @@ package body Sem_Aggr is
       pragma Assert
         (Ada_Version >= Ada_05
           and then Present (Expr)
-          and then Nkind (Expr) = N_Null);
+          and then Known_Null (Expr));
 
       case Ekind (Typ) is
          when E_Array_Type  =>
@@ -3295,7 +3294,7 @@ package body Sem_Aggr is
          Insert_Action
            (Compile_Time_Constraint_Error
               (Expr,
-               "(Ada 2005) NULL not allowed in null-excluding components?"),
+               "(Ada 2005) null not allowed in null-excluding component?"),
             Make_Raise_Constraint_Error (Sloc (Expr),
               Reason => CE_Access_Check_Failed));