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-------------------------------------------------------------------------------
--- --
--- GNAT COMPILER COMPONENTS --
--- --
--- S E M _ C A T --
--- --
--- B o d y --
--- --
--- Copyright (C) 1992-2008, 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- --
--- ware Foundation; either version 3, or (at your option) any later ver- --
--- sion. GNAT is distributed in the hope that it will be useful, but WITH- --
--- OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY --
--- or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License --
--- for more details. You should have received a copy of the GNU General --
--- Public License distributed with GNAT; see file COPYING3. If not, go to --
--- http://www.gnu.org/licenses for a complete copy of the license. --
--- --
--- GNAT was originally developed by the GNAT team at New York University. --
--- Extensive contributions were provided by Ada Core Technologies Inc. --
--- --
-------------------------------------------------------------------------------
-
-with Atree; use Atree;
-with Debug; use Debug;
-with Einfo; use Einfo;
-with Elists; use Elists;
-with Errout; use Errout;
-with Exp_Disp; use Exp_Disp;
-with Fname; use Fname;
-with Lib; use Lib;
-with Namet; use Namet;
-with Nlists; use Nlists;
-with Opt; use Opt;
-with Sem; use Sem;
-with Sem_Eval; use Sem_Eval;
-with Sem_Util; use Sem_Util;
-with Sinfo; use Sinfo;
-with Snames; use Snames;
-with Stand; use Stand;
-
-package body Sem_Cat is
-
- -----------------------
- -- Local Subprograms --
- -----------------------
-
- procedure Check_Categorization_Dependencies
- (Unit_Entity : Entity_Id;
- Depended_Entity : Entity_Id;
- Info_Node : Node_Id;
- Is_Subunit : Boolean);
- -- This procedure checks that the categorization of a lib unit and that
- -- of the depended unit satisfy dependency restrictions.
- -- The depended_entity can be the entity in a with_clause item, in which
- -- case Info_Node denotes that item. The depended_entity can also be the
- -- parent unit of a child unit, in which case Info_Node is the declaration
- -- of the child unit. The error message is posted on Info_Node, and is
- -- specialized if Is_Subunit is true.
-
- procedure Check_Non_Static_Default_Expr
- (Type_Def : Node_Id;
- Obj_Decl : Node_Id);
- -- Iterate through the component list of a record definition, check
- -- that no component is declared with a nonstatic default value.
- -- If a nonstatic default exists, report an error on Obj_Decl.
-
- -- Iterate through the component list of a record definition, check
- -- that no component is declared with a non-static default value.
-
- function Missing_Read_Write_Attributes (E : Entity_Id) return Boolean;
- -- Return True if the entity or one of its subcomponents is of an access
- -- type that does not have user-defined Read and Write attributes visible
- -- at any place.
-
- function In_RCI_Declaration (N : Node_Id) return Boolean;
- -- Determines if a declaration is within the visible part of a Remote
- -- Call Interface compilation unit, for semantic checking purposes only,
- -- (returns false within an instance and within the package body).
-
- function In_RT_Declaration return Boolean;
- -- Determines if current scope is within a Remote Types compilation unit,
- -- for semantic checking purposes.
-
- function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean;
- -- Returns true if the entity is a type whose full view is a non-remote
- -- access type, for the purpose of enforcing E.2.2(8) rules.
-
- function In_Shared_Passive_Unit return Boolean;
- -- Determines if current scope is within a Shared Passive compilation unit
-
- function Static_Discriminant_Expr (L : List_Id) return Boolean;
- -- Iterate through the list of discriminants to check if any of them
- -- contains non-static default expression, which is a violation in
- -- a preelaborated library unit.
-
- procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id);
- -- Check validity of declaration if RCI or RT unit. It should not contain
- -- the declaration of an access-to-object type unless it is a general
- -- access type that designates a class-wide limited private type. There are
- -- also constraints about the primitive subprograms of the class-wide type.
- -- RM E.2 (9, 13, 14)
-
- ---------------------------------------
- -- Check_Categorization_Dependencies --
- ---------------------------------------
-
- procedure Check_Categorization_Dependencies
- (Unit_Entity : Entity_Id;
- Depended_Entity : Entity_Id;
- Info_Node : Node_Id;
- Is_Subunit : Boolean)
- is
- N : constant Node_Id := Info_Node;
-
- -- Here we define an enumeration type to represent categorization types,
- -- ordered so that a unit with a given categorization can only WITH
- -- units with lower or equal categorization type.
-
- -- Note that we take advantage of E.2(14) to define a category
- -- Preelaborated and treat pragma Preelaborate as a categorization
- -- pragma that defines that category.
-
- type Categorization is
- (Pure,
- Shared_Passive,
- Remote_Types,
- Remote_Call_Interface,
- Preelaborated,
- Normal);
-
- function Get_Categorization (E : Entity_Id) return Categorization;
- -- Check categorization flags from entity, and return in the form
- -- of the lowest value of the Categorization type that applies to E.
-
- ------------------------
- -- Get_Categorization --
- ------------------------
-
- function Get_Categorization (E : Entity_Id) return Categorization is
- begin
- -- Get the lowest categorization that corresponds to E. Note that
- -- nothing prevents several (different) categorization pragmas
- -- to apply to the same library unit, in which case the unit has
- -- all associated categories, so we need to be careful here to
- -- check pragmas in proper Categorization order in order to
- -- return the lowest applicable value.
-
- -- Ignore Pure specification if set by pragma Pure_Function
-
- if Is_Pure (E)
- and then not
- (Has_Pragma_Pure_Function (E) and not Has_Pragma_Pure (E))
- then
- return Pure;
-
- elsif Is_Shared_Passive (E) then
- return Shared_Passive;
-
- elsif Is_Remote_Types (E) then
- return Remote_Types;
-
- elsif Is_Remote_Call_Interface (E) then
- return Remote_Call_Interface;
-
- elsif Is_Preelaborated (E) then
- return Preelaborated;
-
- else
- return Normal;
- end if;
- end Get_Categorization;
-
- Unit_Category : Categorization;
- With_Category : Categorization;
-
- -- Start of processing for Check_Categorization_Dependencies
-
- begin
- -- Intrinsic subprograms are preelaborated, so do not impose any
- -- categorization dependencies.
-
- if Is_Intrinsic_Subprogram (Depended_Entity) then
- return;
- end if;
-
- Unit_Category := Get_Categorization (Unit_Entity);
- With_Category := Get_Categorization (Depended_Entity);
-
- -- These messages are warnings in GNAT mode, to allow it to be
- -- judiciously turned off. Otherwise it is a real error.
-
- Error_Msg_Warn := GNAT_Mode;
-
- -- Check for possible error
-
- if With_Category > Unit_Category then
-
- -- Special case: Remote_Types and Remote_Call_Interface are allowed
- -- to be with'ed in package body.
-
- if (Unit_Category = Remote_Types
- or else Unit_Category = Remote_Call_Interface)
- and then In_Package_Body (Unit_Entity)
- then
- null;
-
- -- Here we have an error
-
- else
- -- Don't give error if main unit is not an internal unit, and the
- -- unit generating the message is an internal unit. This is the
- -- situation in which such messages would be ignored in any case,
- -- so it is convenient not to generate them (since it causes
- -- annoying interference with debugging).
-
- if Is_Internal_File_Name (Unit_File_Name (Current_Sem_Unit))
- and then not Is_Internal_File_Name (Unit_File_Name (Main_Unit))
- then
- return;
-
- -- Subunit case
-
- elsif Is_Subunit then
- Error_Msg_NE
- ("<subunit cannot depend on& " &
- "(parent has wrong categorization)", N, Depended_Entity);
-
- -- Normal unit, not subunit
-
- else
- Error_Msg_NE
- ("<cannot depend on& " &
- "(wrong categorization)", N, Depended_Entity);
- end if;
-
- -- Add further explanation for common cases
-
- case Unit_Category is
- when Pure =>
- Error_Msg_NE
- ("\<pure unit cannot depend on non-pure unit",
- N, Depended_Entity);
-
- when Preelaborated =>
- Error_Msg_NE
- ("\<preelaborated unit cannot depend on " &
- "non-preelaborated unit",
- N, Depended_Entity);
-
- when others =>
- null;
- end case;
- end if;
- end if;
- end Check_Categorization_Dependencies;
-
- -----------------------------------
- -- Check_Non_Static_Default_Expr --
- -----------------------------------
-
- procedure Check_Non_Static_Default_Expr
- (Type_Def : Node_Id;
- Obj_Decl : Node_Id)
- is
- Recdef : Node_Id;
- Component_Decl : Node_Id;
-
- begin
- if Nkind (Type_Def) = N_Derived_Type_Definition then
- Recdef := Record_Extension_Part (Type_Def);
-
- if No (Recdef) then
- return;
- end if;
-
- else
- Recdef := Type_Def;
- end if;
-
- -- Check that component declarations do not involve:
-
- -- a. a non-static default expression, where the object is
- -- declared to be default initialized.
-
- -- b. a dynamic Itype (discriminants and constraints)
-
- if Null_Present (Recdef) then
- return;
- else
- Component_Decl := First (Component_Items (Component_List (Recdef)));
- end if;
-
- while Present (Component_Decl)
- and then Nkind (Component_Decl) = N_Component_Declaration
- loop
- if Present (Expression (Component_Decl))
- and then Nkind (Expression (Component_Decl)) /= N_Null
- and then not Is_Static_Expression (Expression (Component_Decl))
- then
- Error_Msg_Sloc := Sloc (Component_Decl);
- Error_Msg_F
- ("object in preelaborated unit has non-static default#",
- Obj_Decl);
-
- -- Fix this later ???
-
- -- elsif Has_Dynamic_Itype (Component_Decl) then
- -- Error_Msg_N
- -- ("dynamic type discriminant," &
- -- " constraint in preelaborated unit",
- -- Component_Decl);
- end if;
-
- Next (Component_Decl);
- end loop;
- end Check_Non_Static_Default_Expr;
-
- -------------------------------------
- -- Has_Stream_Attribute_Definition --
- -------------------------------------
-
- function Has_Stream_Attribute_Definition
- (Typ : Entity_Id;
- Nam : TSS_Name_Type;
- At_Any_Place : Boolean := False) return Boolean
- is
- Rep_Item : Node_Id;
- Full_Type : Entity_Id := Typ;
-
- begin
- -- In the case of a type derived from a private view, any specified
- -- stream attributes will be attached to the derived type's underlying
- -- type rather the derived type entity itself (which is itself private).
-
- if Is_Private_Type (Typ)
- and then Is_Derived_Type (Typ)
- and then Present (Full_View (Typ))
- then
- Full_Type := Underlying_Type (Typ);
- end if;
-
- -- We start from the declaration node and then loop until the end of
- -- the list until we find the requested attribute definition clause.
- -- In Ada 2005 mode, clauses are ignored if they are not currently
- -- visible (this is tested using the corresponding Entity, which is
- -- inserted by the expander at the point where the clause occurs),
- -- unless At_Any_Place is true.
-
- Rep_Item := First_Rep_Item (Full_Type);
- while Present (Rep_Item) loop
- if Nkind (Rep_Item) = N_Attribute_Definition_Clause then
- case Chars (Rep_Item) is
- when Name_Read =>
- exit when Nam = TSS_Stream_Read;
-
- when Name_Write =>
- exit when Nam = TSS_Stream_Write;
-
- when Name_Input =>
- exit when Nam = TSS_Stream_Input;
-
- when Name_Output =>
- exit when Nam = TSS_Stream_Output;
-
- when others =>
- null;
-
- end case;
- end if;
-
- Next_Rep_Item (Rep_Item);
- end loop;
-
- -- If At_Any_Place is true, return True if the attribute is available
- -- at any place; if it is false, return True only if the attribute is
- -- currently visible.
-
- return Present (Rep_Item)
- and then (Ada_Version < Ada_05
- or else At_Any_Place
- or else not Is_Hidden (Entity (Rep_Item)));
- end Has_Stream_Attribute_Definition;
-
- ---------------------------
- -- In_Preelaborated_Unit --
- ---------------------------
-
- function In_Preelaborated_Unit return Boolean is
- Unit_Entity : constant Entity_Id := Current_Scope;
- Unit_Kind : constant Node_Kind :=
- Nkind (Unit (Cunit (Current_Sem_Unit)));
-
- begin
- -- There are no constraints on body of remote_call_interface or
- -- remote_types packages.
-
- return (Unit_Entity /= Standard_Standard)
- and then (Is_Preelaborated (Unit_Entity)
- or else Is_Pure (Unit_Entity)
- or else Is_Shared_Passive (Unit_Entity)
- or else
- ((Is_Remote_Types (Unit_Entity)
- or else Is_Remote_Call_Interface (Unit_Entity))
- and then Ekind (Unit_Entity) = E_Package
- and then Unit_Kind /= N_Package_Body
- and then not In_Package_Body (Unit_Entity)
- and then not In_Instance));
- end In_Preelaborated_Unit;
-
- ------------------
- -- In_Pure_Unit --
- ------------------
-
- function In_Pure_Unit return Boolean is
- begin
- return Is_Pure (Current_Scope);
- end In_Pure_Unit;
-
- ------------------------
- -- In_RCI_Declaration --
- ------------------------
-
- function In_RCI_Declaration (N : Node_Id) return Boolean is
- Unit_Entity : constant Entity_Id := Current_Scope;
- Unit_Kind : constant Node_Kind :=
- Nkind (Unit (Cunit (Current_Sem_Unit)));
-
- begin
- -- There are no restrictions on the private part or body
- -- of an RCI unit.
-
- return Is_Remote_Call_Interface (Unit_Entity)
- and then Is_Package_Or_Generic_Package (Unit_Entity)
- and then Unit_Kind /= N_Package_Body
- and then List_Containing (N) =
- Visible_Declarations
- (Specification (Unit_Declaration_Node (Unit_Entity)))
- and then not In_Package_Body (Unit_Entity)
- and then not In_Instance;
-
- -- What about the case of a nested package in the visible part???
- -- This case is missed by the List_Containing check above???
- end In_RCI_Declaration;
-
- -----------------------
- -- In_RT_Declaration --
- -----------------------
-
- function In_RT_Declaration return Boolean is
- Unit_Entity : constant Entity_Id := Current_Scope;
- Unit_Kind : constant Node_Kind :=
- Nkind (Unit (Cunit (Current_Sem_Unit)));
-
- begin
- -- There are no restrictions on the body of a Remote Types unit
-
- return Is_Remote_Types (Unit_Entity)
- and then Is_Package_Or_Generic_Package (Unit_Entity)
- and then Unit_Kind /= N_Package_Body
- and then not In_Package_Body (Unit_Entity)
- and then not In_Instance;
- end In_RT_Declaration;
-
- ----------------------------
- -- In_Shared_Passive_Unit --
- ----------------------------
-
- function In_Shared_Passive_Unit return Boolean is
- Unit_Entity : constant Entity_Id := Current_Scope;
-
- begin
- return Is_Shared_Passive (Unit_Entity);
- end In_Shared_Passive_Unit;
-
- ---------------------------------------
- -- In_Subprogram_Task_Protected_Unit --
- ---------------------------------------
-
- function In_Subprogram_Task_Protected_Unit return Boolean is
- E : Entity_Id;
-
- begin
- -- The following is to verify that a declaration is inside
- -- subprogram, generic subprogram, task unit, protected unit.
- -- Used to validate if a lib. unit is Pure. RM 10.2.1(16).
-
- -- Use scope chain to check successively outer scopes
-
- E := Current_Scope;
- loop
- if Is_Subprogram (E)
- or else
- Is_Generic_Subprogram (E)
- or else
- Is_Concurrent_Type (E)
- then
- return True;
-
- elsif E = Standard_Standard then
- return False;
- end if;
-
- E := Scope (E);
- end loop;
- end In_Subprogram_Task_Protected_Unit;
-
- -------------------------------
- -- Is_Non_Remote_Access_Type --
- -------------------------------
-
- function Is_Non_Remote_Access_Type (E : Entity_Id) return Boolean is
- U_E : constant Entity_Id := Underlying_Type (E);
- begin
- if No (U_E) then
-
- -- This case arises for the case of a generic formal type, in which
- -- case E.2.2(8) rules will be enforced at instantiation time.
-
- return False;
- end if;
-
- return Is_Access_Type (U_E)
- and then not Is_Remote_Access_To_Class_Wide_Type (U_E)
- and then not Is_Remote_Access_To_Subprogram_Type (U_E);
- end Is_Non_Remote_Access_Type;
-
- ----------------------------------
- -- Missing_Read_Write_Attribute --
- ----------------------------------
-
- function Missing_Read_Write_Attributes (E : Entity_Id) return Boolean is
- Component : Entity_Id;
- Component_Type : Entity_Id;
- U_E : constant Entity_Id := Underlying_Type (E);
-
- function Has_Read_Write_Attributes (E : Entity_Id) return Boolean;
- -- Return True if entity has attribute definition clauses for Read and
- -- Write attributes that are visible at some place.
-
- -------------------------------
- -- Has_Read_Write_Attributes --
- -------------------------------
-
- function Has_Read_Write_Attributes (E : Entity_Id) return Boolean is
- begin
- return True
- and then Has_Stream_Attribute_Definition (E,
- TSS_Stream_Read, At_Any_Place => True)
- and then Has_Stream_Attribute_Definition (E,
- TSS_Stream_Write, At_Any_Place => True);
- end Has_Read_Write_Attributes;
-
- -- Start of processing for Missing_Read_Write_Attributes
-
- begin
- if No (U_E) then
- return False;
-
- elsif Has_Read_Write_Attributes (E)
- or else Has_Read_Write_Attributes (U_E)
- then
- return False;
-
- elsif Is_Non_Remote_Access_Type (U_E) then
- return True;
- end if;
-
- if Is_Record_Type (U_E) then
- Component := First_Entity (U_E);
- while Present (Component) loop
- if not Is_Tag (Component) then
- Component_Type := Etype (Component);
-
- if Missing_Read_Write_Attributes (Component_Type) then
- return True;
- end if;
- end if;
-
- Next_Entity (Component);
- end loop;
- end if;
-
- return False;
- end Missing_Read_Write_Attributes;
-
- -------------------------------------
- -- Set_Categorization_From_Pragmas --
- -------------------------------------
-
- procedure Set_Categorization_From_Pragmas (N : Node_Id) is
- P : constant Node_Id := Parent (N);
- S : constant Entity_Id := Current_Scope;
-
- procedure Set_Parents (Visibility : Boolean);
- -- If this is a child instance, the parents are not immediately
- -- visible during analysis. Make them momentarily visible so that
- -- the argument of the pragma can be resolved properly, and reset
- -- afterwards.
-
- -----------------
- -- Set_Parents --
- -----------------
-
- procedure Set_Parents (Visibility : Boolean) is
- Par : Entity_Id;
- begin
- Par := Scope (S);
- while Present (Par) and then Par /= Standard_Standard loop
- Set_Is_Immediately_Visible (Par, Visibility);
- Par := Scope (Par);
- end loop;
- end Set_Parents;
-
- -- Start of processing for Set_Categorization_From_Pragmas
-
- begin
- -- Deal with categorization pragmas in Pragmas of Compilation_Unit.
- -- The purpose is to set categorization flags before analyzing the
- -- unit itself, so as to diagnose violations of categorization as
- -- we process each declaration, even though the pragma appears after
- -- the unit.
-
- if Nkind (P) /= N_Compilation_Unit then
- return;
- end if;
-
- declare
- PN : Node_Id;
-
- begin
- if Is_Child_Unit (S)
- and then Is_Generic_Instance (S)
- then
- Set_Parents (True);
- end if;
-
- PN := First (Pragmas_After (Aux_Decls_Node (P)));
- while Present (PN) loop
-
- -- Skip implicit types that may have been introduced by
- -- previous analysis.
-
- if Nkind (PN) = N_Pragma then
- case Get_Pragma_Id (PN) is
- when Pragma_All_Calls_Remote |
- Pragma_Preelaborate |
- Pragma_Pure |
- Pragma_Remote_Call_Interface |
- Pragma_Remote_Types |
- Pragma_Shared_Passive => Analyze (PN);
- when others => null;
- end case;
- end if;
-
- Next (PN);
- end loop;
-
- if Is_Child_Unit (S)
- and then Is_Generic_Instance (S)
- then
- Set_Parents (False);
- end if;
- end;
- end Set_Categorization_From_Pragmas;
-
- -----------------------------------
- -- Set_Categorization_From_Scope --
- -----------------------------------
-
- procedure Set_Categorization_From_Scope (E : Entity_Id; Scop : Entity_Id) is
- Declaration : Node_Id := Empty;
- Specification : Node_Id := Empty;
-
- begin
- Set_Is_Pure (E,
- Is_Pure (Scop) and then Is_Library_Level_Entity (E));
-
- if not Is_Remote_Call_Interface (E) then
- if Ekind (E) in Subprogram_Kind then
- Declaration := Unit_Declaration_Node (E);
-
- if Nkind (Declaration) = N_Subprogram_Body
- or else
- Nkind (Declaration) = N_Subprogram_Renaming_Declaration
- then
- Specification := Corresponding_Spec (Declaration);
- end if;
- end if;
-
- -- A subprogram body or renaming-as-body is a remote call
- -- interface if it serves as the completion of a subprogram
- -- declaration that is a remote call interface.
-
- if Nkind (Specification) in N_Entity then
- Set_Is_Remote_Call_Interface
- (E, Is_Remote_Call_Interface (Specification));
-
- -- A subprogram declaration is a remote call interface when it is
- -- declared within the visible part of, or declared by, a library
- -- unit declaration that is a remote call interface.
-
- else
- Set_Is_Remote_Call_Interface
- (E, Is_Remote_Call_Interface (Scop)
- and then not (In_Private_Part (Scop)
- or else In_Package_Body (Scop)));
- end if;
- end if;
-
- Set_Is_Remote_Types
- (E, Is_Remote_Types (Scop)
- and then not (In_Private_Part (Scop)
- or else In_Package_Body (Scop)));
- end Set_Categorization_From_Scope;
-
- ------------------------------
- -- Static_Discriminant_Expr --
- ------------------------------
-
- -- We need to accommodate a Why_Not_Static call somehow here ???
-
- function Static_Discriminant_Expr (L : List_Id) return Boolean is
- Discriminant_Spec : Node_Id;
-
- begin
- Discriminant_Spec := First (L);
- while Present (Discriminant_Spec) loop
- if Present (Expression (Discriminant_Spec))
- and then not Is_Static_Expression (Expression (Discriminant_Spec))
- then
- return False;
- end if;
-
- Next (Discriminant_Spec);
- end loop;
-
- return True;
- end Static_Discriminant_Expr;
-
- --------------------------------------
- -- Validate_Access_Type_Declaration --
- --------------------------------------
-
- procedure Validate_Access_Type_Declaration (T : Entity_Id; N : Node_Id) is
- Def : constant Node_Id := Type_Definition (N);
-
- begin
- case Nkind (Def) is
-
- -- Access to subprogram case
-
- when N_Access_To_Subprogram_Definition =>
-
- -- A pure library_item must not contain the declaration of a
- -- named access type, except within a subprogram, generic
- -- subprogram, task unit, or protected unit (RM 10.2.1(16)).
-
- -- This test is skipped in Ada 2005 (see AI-366)
-
- if Ada_Version < Ada_05
- and then Comes_From_Source (T)
- and then In_Pure_Unit
- and then not In_Subprogram_Task_Protected_Unit
- then
- Error_Msg_N ("named access type not allowed in pure unit", T);
- end if;
-
- -- Access to object case
-
- when N_Access_To_Object_Definition =>
- if Comes_From_Source (T)
- and then In_Pure_Unit
- and then not In_Subprogram_Task_Protected_Unit
- then
- -- We can't give the message yet, since the type is not frozen
- -- and in Ada 2005 mode, access types are allowed in pure units
- -- if the type has no storage pool (see AI-366). So we set a
- -- flag which will be checked at freeze time.
-
- Set_Is_Pure_Unit_Access_Type (T);
- end if;
-
- -- Check for RCI or RT unit type declaration: declaration of an
- -- access-to-object type is illegal unless it is a general access
- -- type that designates a class-wide limited private type.
- -- Note that constraints on the primitive subprograms of the
- -- designated tagged type are not enforced here but in
- -- Validate_RACW_Primitives, which is done separately because the
- -- designated type might not be frozen (and therefore its
- -- primitive operations might not be completely known) at the
- -- point of the RACW declaration.
-
- Validate_Remote_Access_Object_Type_Declaration (T);
-
- -- Check for shared passive unit type declaration. It should
- -- not contain the declaration of access to class wide type,
- -- access to task type and access to protected type with entry.
-
- Validate_SP_Access_Object_Type_Decl (T);
-
- when others =>
- null;
- end case;
-
- -- Set categorization flag from package on entity as well, to allow
- -- easy checks later on for required validations of RCI or RT units.
- -- This is only done for entities that are in the original source.
-
- if Comes_From_Source (T)
- and then not (In_Package_Body (Scope (T))
- or else In_Private_Part (Scope (T)))
- then
- Set_Is_Remote_Call_Interface
- (T, Is_Remote_Call_Interface (Scope (T)));
- Set_Is_Remote_Types
- (T, Is_Remote_Types (Scope (T)));
- end if;
- end Validate_Access_Type_Declaration;
-
- ----------------------------
- -- Validate_Ancestor_Part --
- ----------------------------
-
- procedure Validate_Ancestor_Part (N : Node_Id) is
- A : constant Node_Id := Ancestor_Part (N);
- T : constant Entity_Id := Entity (A);
-
- begin
- if In_Preelaborated_Unit
- and then not In_Subprogram_Or_Concurrent_Unit
- and then (not Inside_A_Generic
- or else Present (Enclosing_Generic_Body (N)))
- then
- -- If the type is private, it must have the Ada 2005 pragma
- -- Has_Preelaborable_Initialization.
- -- The check is omitted within predefined units. This is probably
- -- obsolete code to fix the Ada95 weakness in this area ???
-
- if Is_Private_Type (T)
- and then not Has_Pragma_Preelab_Init (T)
- and then not Is_Internal_File_Name
- (Unit_File_Name (Get_Source_Unit (N)))
- then
- Error_Msg_N
- ("private ancestor type not allowed in preelaborated unit", A);
-
- elsif Is_Record_Type (T) then
- if Nkind (Parent (T)) = N_Full_Type_Declaration then
- Check_Non_Static_Default_Expr
- (Type_Definition (Parent (T)), A);
- end if;
- end if;
- end if;
- end Validate_Ancestor_Part;
-
- ----------------------------------------
- -- Validate_Categorization_Dependency --
- ----------------------------------------
-
- procedure Validate_Categorization_Dependency
- (N : Node_Id;
- E : Entity_Id)
- is
- K : constant Node_Kind := Nkind (N);
- P : Node_Id := Parent (N);
- U : Entity_Id := E;
- Is_Subunit : constant Boolean := Nkind (P) = N_Subunit;
-
- begin
- -- Only validate library units and subunits. For subunits, checks
- -- concerning withed units apply to the parent compilation unit.
-
- if Is_Subunit then
- P := Parent (P);
- U := Scope (E);
-
- while Present (U)
- and then not Is_Compilation_Unit (U)
- and then not Is_Child_Unit (U)
- loop
- U := Scope (U);
- end loop;
- end if;
-
- if Nkind (P) /= N_Compilation_Unit then
- return;
- end if;
-
- -- Body of RCI unit does not need validation
-
- if Is_Remote_Call_Interface (E)
- and then (Nkind (N) = N_Package_Body
- or else Nkind (N) = N_Subprogram_Body)
- then
- return;
- end if;
-
- -- Ada 2005 (AI-50217): Process explicit non-limited with_clauses
-
- declare
- Item : Node_Id;
- Entity_Of_Withed : Entity_Id;
-
- begin
- Item := First (Context_Items (P));
- while Present (Item) loop
- if Nkind (Item) = N_With_Clause
- and then not (Implicit_With (Item)
- or else Limited_Present (Item))
- then
- Entity_Of_Withed := Entity (Name (Item));
- Check_Categorization_Dependencies
- (U, Entity_Of_Withed, Item, Is_Subunit);
- end if;
-
- Next (Item);
- end loop;
- end;
-
- -- Child depends on parent; therefore parent should also be categorized
- -- and satisfy the dependency hierarchy.
-
- -- Check if N is a child spec
-
- if (K in N_Generic_Declaration or else
- K in N_Generic_Instantiation or else
- K in N_Generic_Renaming_Declaration or else
- K = N_Package_Declaration or else
- K = N_Package_Renaming_Declaration or else
- K = N_Subprogram_Declaration or else
- K = N_Subprogram_Renaming_Declaration)
- and then Present (Parent_Spec (N))
- then
- Check_Categorization_Dependencies (E, Scope (E), N, False);
-
- -- Verify that public child of an RCI library unit must also be an
- -- RCI library unit (RM E.2.3(15)).
-
- if Is_Remote_Call_Interface (Scope (E))
- and then not Private_Present (P)
- and then not Is_Remote_Call_Interface (E)
- then
- Error_Msg_N ("public child of rci unit must also be rci unit", N);
- end if;
- end if;
- end Validate_Categorization_Dependency;
-
- --------------------------------
- -- Validate_Controlled_Object --
- --------------------------------
-
- procedure Validate_Controlled_Object (E : Entity_Id) is
- begin
- -- Don't need this check in Ada 2005 mode, where this is all taken
- -- care of by the mechanism for Preelaborable Initialization.
-
- if Ada_Version >= Ada_05 then
- return;
- end if;
-
- -- For now, never apply this check for internal GNAT units, since we
- -- have a number of cases in the library where we are stuck with objects
- -- of this type, and the RM requires Preelaborate.
-
- -- For similar reasons, we only do this check for source entities, since
- -- we generate entities of this type in some situations.
-
- -- Note that the 10.2.1(9) restrictions are not relevant to us anyway.
- -- We have to enforce them for RM compatibility, but we have no trouble
- -- accepting these objects and doing the right thing. Note that there is
- -- no requirement that Preelaborate not actually generate any code!
-
- if In_Preelaborated_Unit
- and then not Debug_Flag_PP
- and then Comes_From_Source (E)
- and then not
- Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (E)))
- and then (not Inside_A_Generic
- or else Present (Enclosing_Generic_Body (E)))
- and then not Is_Protected_Type (Etype (E))
- then
- Error_Msg_N
- ("library level controlled object not allowed in " &
- "preelaborated unit", E);
- end if;
- end Validate_Controlled_Object;
-
- --------------------------------------
- -- Validate_Null_Statement_Sequence --
- --------------------------------------
-
- procedure Validate_Null_Statement_Sequence (N : Node_Id) is
- Item : Node_Id;
-
- begin
- if In_Preelaborated_Unit then
- Item := First (Statements (Handled_Statement_Sequence (N)));
- while Present (Item) loop
- if Nkind (Item) /= N_Label
- and then Nkind (Item) /= N_Null_Statement
- then
- -- In GNAT mode, this is a warning, allowing the run-time
- -- to judiciously bypass this error condition.
-
- Error_Msg_Warn := GNAT_Mode;
- Error_Msg_N
- ("<statements not allowed in preelaborated unit", Item);
-
- exit;
- end if;
-
- Next (Item);
- end loop;
- end if;
- end Validate_Null_Statement_Sequence;
-
- ---------------------------------
- -- Validate_Object_Declaration --
- ---------------------------------
-
- procedure Validate_Object_Declaration (N : Node_Id) is
- Id : constant Entity_Id := Defining_Identifier (N);
- E : constant Node_Id := Expression (N);
- Odf : constant Node_Id := Object_Definition (N);
- T : constant Entity_Id := Etype (Id);
-
- begin
- -- Verify that any access to subprogram object does not have in its
- -- subprogram profile access type parameters or limited parameters
- -- without Read and Write attributes (E.2.3(13)).
-
- Validate_RCI_Subprogram_Declaration (N);
-
- -- Check that if we are in preelaborated elaboration code, then we
- -- do not have an instance of a default initialized private, task or
- -- protected object declaration which would violate (RM 10.2.1(9)).
- -- Note that constants are never default initialized (and the test
- -- below also filters out deferred constants). A variable is default
- -- initialized if it does *not* have an initialization expression.
-
- -- Filter out cases that are not declaration of a variable from source
-
- if Nkind (N) /= N_Object_Declaration
- or else Constant_Present (N)
- or else not Comes_From_Source (Id)
- then
- return;
- end if;
-
- -- Exclude generic specs from the checks (this will get rechecked
- -- on instantiations).
-
- if Inside_A_Generic
- and then No (Enclosing_Generic_Body (Id))
- then
- return;
- end if;
-
- -- Required checks for declaration that is in a preelaborated
- -- package and is not within some subprogram.
-
- if In_Preelaborated_Unit
- and then not In_Subprogram_Or_Concurrent_Unit
- then
- -- Check for default initialized variable case. Note that in
- -- accordance with (RM B.1(24)) imported objects are not
- -- subject to default initialization.
- -- If the initialization does not come from source and is an
- -- aggregate, it is a static initialization that replaces an
- -- implicit call, and must be treated as such.
-
- if Present (E)
- and then
- (Comes_From_Source (E) or else Nkind (E) /= N_Aggregate)
- then
- null;
-
- elsif Is_Imported (Id) then
- null;
-
- else
- declare
- Ent : Entity_Id := T;
-
- begin
- -- An array whose component type is a record with nonstatic
- -- default expressions is a violation, so we get the array's
- -- component type.
-
- if Is_Array_Type (Ent) then
- declare
- Comp_Type : Entity_Id;
-
- begin
- Comp_Type := Component_Type (Ent);
- while Is_Array_Type (Comp_Type) loop
- Comp_Type := Component_Type (Comp_Type);
- end loop;
-
- Ent := Comp_Type;
- end;
- end if;
-
- -- Object decl. that is of record type and has no default expr.
- -- should check if there is any non-static default expression
- -- in component decl. of the record type decl.
-
- if Is_Record_Type (Ent) then
- if Nkind (Parent (Ent)) = N_Full_Type_Declaration then
- Check_Non_Static_Default_Expr
- (Type_Definition (Parent (Ent)), N);
-
- elsif Nkind (Odf) = N_Subtype_Indication
- and then not Is_Array_Type (T)
- and then not Is_Private_Type (T)
- then
- Check_Non_Static_Default_Expr (Type_Definition
- (Parent (Entity (Subtype_Mark (Odf)))), N);
- end if;
- end if;
-
- -- Check for invalid use of private object. Note that Ada 2005
- -- AI-161 modifies the rules for Ada 2005, including the use of
- -- the new pragma Preelaborable_Initialization.
-
- if Is_Private_Type (Ent)
- or else Depends_On_Private (Ent)
- then
- -- Case where type has preelaborable initialization which
- -- means that a pragma Preelaborable_Initialization was
- -- given for the private type.
-
- if Has_Preelaborable_Initialization (Ent) then
-
- -- But for the predefined units, we will ignore this
- -- status unless we are in Ada 2005 mode since we want
- -- Ada 95 compatible behavior, in which the entities
- -- marked with this pragma in the predefined library are
- -- not treated specially.
-
- if Ada_Version < Ada_05 then
- Error_Msg_N
- ("private object not allowed in preelaborated unit",
- N);
- Error_Msg_N ("\(would be legal in Ada 2005 mode)", N);
- end if;
-
- -- Type does not have preelaborable initialization
-
- else
- -- We allow this when compiling in GNAT mode to make life
- -- easier for some cases where it would otherwise be hard
- -- to be exactly valid Ada.
-
- if not GNAT_Mode then
- Error_Msg_N
- ("private object not allowed in preelaborated unit",
- N);
-
- -- Add a message if it would help to provide a pragma
- -- Preelaborable_Initialization on the type of the
- -- object (which would make it legal in Ada 2005).
-
- -- If the type has no full view (generic type, or
- -- previous error), the warning does not apply.
-
- if Is_Private_Type (Ent)
- and then Present (Full_View (Ent))
- and then
- Has_Preelaborable_Initialization (Full_View (Ent))
- then
- Error_Msg_Sloc := Sloc (Ent);
-
- if Ada_Version >= Ada_05 then
- Error_Msg_NE
- ("\would be legal if pragma Preelaborable_" &
- "Initialization given for & #", N, Ent);
- else
- Error_Msg_NE
- ("\would be legal in Ada 2005 if pragma " &
- "Preelaborable_Initialization given for & #",
- N, Ent);
- end if;
- end if;
- end if;
- end if;
-
- -- Access to Task or Protected type
-
- elsif Is_Entity_Name (Odf)
- and then Present (Etype (Odf))
- and then Is_Access_Type (Etype (Odf))
- then
- Ent := Designated_Type (Etype (Odf));
-
- elsif Is_Entity_Name (Odf) then
- Ent := Entity (Odf);
-
- elsif Nkind (Odf) = N_Subtype_Indication then
- Ent := Etype (Subtype_Mark (Odf));
-
- elsif
- Nkind (Odf) = N_Constrained_Array_Definition
- then
- Ent := Component_Type (T);
-
- -- else
- -- return;
- end if;
-
- if Is_Task_Type (Ent)
- or else (Is_Protected_Type (Ent) and then Has_Entries (Ent))
- then
- Error_Msg_N
- ("concurrent object not allowed in preelaborated unit",
- N);
- return;
- end if;
- end;
- end if;
-
- -- Non-static discriminant not allowed in preelaborated unit
- -- Controlled object of a type with a user-defined Initialize
- -- is forbidden as well.
-
- if Is_Record_Type (Etype (Id)) then
- declare
- ET : constant Entity_Id := Etype (Id);
- EE : constant Entity_Id := Etype (Etype (Id));
- PEE : Node_Id;
-
- begin
- if Has_Discriminants (ET)
- and then Present (EE)
- then
- PEE := Parent (EE);
-
- if Nkind (PEE) = N_Full_Type_Declaration
- and then not Static_Discriminant_Expr
- (Discriminant_Specifications (PEE))
- then
- Error_Msg_N
- ("non-static discriminant in preelaborated unit",
- PEE);
- end if;
- end if;
-
- if Has_Overriding_Initialize (ET) then
- Error_Msg_NE
- ("controlled type& does not have"
- & " preelaborable initialization", N, ET);
- end if;
- end;
-
- end if;
- end if;
-
- -- A pure library_item must not contain the declaration of any variable
- -- except within a subprogram, generic subprogram, task unit, or
- -- protected unit (RM 10.2.1(16)).
-
- if In_Pure_Unit
- and then not In_Subprogram_Task_Protected_Unit
- then
- Error_Msg_N ("declaration of variable not allowed in pure unit", N);
-
- -- The visible part of an RCI library unit must not contain the
- -- declaration of a variable (RM E.1.3(9))
-
- elsif In_RCI_Declaration (N) then
- Error_Msg_N ("declaration of variable not allowed in rci unit", N);
-
- -- The visible part of a Shared Passive library unit must not contain
- -- the declaration of a variable (RM E.2.2(7))
-
- elsif In_RT_Declaration then
- Error_Msg_N
- ("variable declaration not allowed in remote types unit", N);
- end if;
-
- end Validate_Object_Declaration;
-
- ------------------------------
- -- Validate_RACW_Primitives --
- ------------------------------
-
- procedure Validate_RACW_Primitives (T : Entity_Id) is
- Desig_Type : Entity_Id;
- Primitive_Subprograms : Elist_Id;
- Subprogram_Elmt : Elmt_Id;
- Subprogram : Entity_Id;
- Param_Spec : Node_Id;
- Param : Entity_Id;
- Param_Type : Entity_Id;
- Rtyp : Node_Id;
-
- procedure Illegal_RACW (Msg : String; N : Node_Id);
- -- Diagnose that T is illegal because of the given reason, associated
- -- with the location of node N.
-
- Illegal_RACW_Message_Issued : Boolean := False;
- -- Set True once Illegal_RACW has been called
-
- ------------------
- -- Illegal_RACW --
- ------------------
-
- procedure Illegal_RACW (Msg : String; N : Node_Id) is
- begin
- if not Illegal_RACW_Message_Issued then
- Error_Msg_N
- ("illegal remote access to class-wide type&", T);
- Illegal_RACW_Message_Issued := True;
- end if;
-
- Error_Msg_Sloc := Sloc (N);
- Error_Msg_N ("\\" & Msg & " in primitive#", T);
- end Illegal_RACW;
-
- -- Start of processing for Validate_RACW_Primitives
-
- begin
- Desig_Type := Etype (Designated_Type (T));
-
- Primitive_Subprograms := Primitive_Operations (Desig_Type);
-
- Subprogram_Elmt := First_Elmt (Primitive_Subprograms);
- while Subprogram_Elmt /= No_Elmt loop
- Subprogram := Node (Subprogram_Elmt);
-
- if Is_Predefined_Dispatching_Operation (Subprogram)
- or else Is_Hidden (Subprogram)
- then
- goto Next_Subprogram;
- end if;
-
- -- Check return type
-
- if Ekind (Subprogram) = E_Function then
- Rtyp := Etype (Subprogram);
-
- if Has_Controlling_Result (Subprogram) then
- null;
-
- elsif Ekind (Rtyp) = E_Anonymous_Access_Type then
- Illegal_RACW ("anonymous access result", Rtyp);
-
- elsif Is_Limited_Type (Rtyp) then
- if No (TSS (Rtyp, TSS_Stream_Read))
- or else
- No (TSS (Rtyp, TSS_Stream_Write))
- then
- Illegal_RACW
- ("limited return type must have Read and Write attributes",
- Parent (Subprogram));
- Explain_Limited_Type (Rtyp, Parent (Subprogram));
-
- -- Check that the return type supports external streaming.
- -- Note that the language of the standard (E.2.2(14)) does not
- -- explicitly mention that case, but it really does not make
- -- sense to return a value containing a local access type.
-
- elsif Missing_Read_Write_Attributes (Rtyp)
- and then not Error_Posted (Rtyp)
- then
- Illegal_RACW ("return type containing non-remote access "
- & "must have Read and Write attributes",
- Parent (Subprogram));
- end if;
-
- end if;
- end if;
-
- Param := First_Formal (Subprogram);
- while Present (Param) loop
-
- -- Now find out if this parameter is a controlling parameter
-
- Param_Spec := Parent (Param);
- Param_Type := Etype (Param);
-
- if Is_Controlling_Formal (Param) then
-
- -- It is a controlling parameter, so specific checks below
- -- do not apply.
-
- null;
-
- elsif Ekind (Param_Type) = E_Anonymous_Access_Type
- or else Ekind (Param_Type) = E_Anonymous_Access_Subprogram_Type
- then
- -- From RM E.2.2(14), no anonymous access parameter other than
- -- controlling ones may be used (because an anonymous access
- -- type never supports external streaming).
-
- Illegal_RACW ("non-controlling access parameter", Param_Spec);
-
- elsif Is_Limited_Type (Param_Type) then
-
- -- Not a controlling parameter, so type must have Read and
- -- Write attributes.
-
- if No (TSS (Param_Type, TSS_Stream_Read))
- or else
- No (TSS (Param_Type, TSS_Stream_Write))
- then
- Illegal_RACW
- ("limited formal must have Read and Write attributes",
- Param_Spec);
- Explain_Limited_Type (Param_Type, Param_Spec);
- end if;
-
- elsif Missing_Read_Write_Attributes (Param_Type)
- and then not Error_Posted (Param_Type)
- then
- Illegal_RACW ("parameter containing non-remote access "
- & "must have Read and Write attributes", Param_Spec);
- end if;
-
- -- Check next parameter in this subprogram
-
- Next_Formal (Param);
- end loop;
-
- <<Next_Subprogram>>
- Next_Elmt (Subprogram_Elmt);
- end loop;
- end Validate_RACW_Primitives;
-
- -------------------------------
- -- Validate_RCI_Declarations --
- -------------------------------
-
- procedure Validate_RCI_Declarations (P : Entity_Id) is
- E : Entity_Id;
-
- begin
- E := First_Entity (P);
- while Present (E) loop
- if Comes_From_Source (E) then
- if Is_Limited_Type (E) then
- Error_Msg_N
- ("limited type not allowed in rci unit", Parent (E));
- Explain_Limited_Type (E, Parent (E));
-
- elsif Ekind (E) = E_Generic_Function
- or else Ekind (E) = E_Generic_Package
- or else Ekind (E) = E_Generic_Procedure
- then
- Error_Msg_N ("generic declaration not allowed in rci unit",
- Parent (E));
-
- elsif (Ekind (E) = E_Function
- or else Ekind (E) = E_Procedure)
- and then Has_Pragma_Inline (E)
- then
- Error_Msg_N
- ("inlined subprogram not allowed in rci unit", Parent (E));
-
- -- Inner packages that are renamings need not be checked. Generic
- -- RCI packages are subject to the checks, but entities that come
- -- from formal packages are not part of the visible declarations
- -- of the package and are not checked.
-
- elsif Ekind (E) = E_Package then
- if Present (Renamed_Entity (E)) then
- null;
-
- elsif Ekind (P) /= E_Generic_Package
- or else List_Containing (Unit_Declaration_Node (E)) /=
- Generic_Formal_Declarations
- (Unit_Declaration_Node (P))
- then
- Validate_RCI_Declarations (E);
- end if;
- end if;
- end if;
-
- Next_Entity (E);
- end loop;
- end Validate_RCI_Declarations;
-
- -----------------------------------------
- -- Validate_RCI_Subprogram_Declaration --
- -----------------------------------------
-
- procedure Validate_RCI_Subprogram_Declaration (N : Node_Id) is
- K : constant Node_Kind := Nkind (N);
- Profile : List_Id;
- Id : Node_Id;
- Param_Spec : Node_Id;
- Param_Type : Entity_Id;
- Base_Param_Type : Entity_Id;
- Base_Under_Type : Entity_Id;
- Type_Decl : Node_Id;
- Error_Node : Node_Id := N;
-
- begin
- -- This procedure enforces rules on subprogram and access to subprogram
- -- declarations in RCI units. These rules do not apply to expander
- -- generated routines, which are not remote subprograms. It is called:
-
- -- 1. from Analyze_Subprogram_Declaration.
- -- 2. from Validate_Object_Declaration (access to subprogram).
-
- if not (Comes_From_Source (N) and then In_RCI_Declaration (N)) then
- return;
- end if;
-
- if K = N_Subprogram_Declaration then
- Profile := Parameter_Specifications (Specification (N));
-
- else pragma Assert (K = N_Object_Declaration);
-
- -- The above assertion is dubious, the visible declarations of an
- -- RCI unit never contain an object declaration, this should be an
- -- ACCESS-to-object declaration???
-
- Id := Defining_Identifier (N);
-
- if Nkind (Id) = N_Defining_Identifier
- and then Nkind (Parent (Etype (Id))) = N_Full_Type_Declaration
- and then Ekind (Etype (Id)) = E_Access_Subprogram_Type
- then
- Profile :=
- Parameter_Specifications (Type_Definition (Parent (Etype (Id))));
- else
- return;
- end if;
- end if;
-
- -- Iterate through the parameter specification list, checking that
- -- no access parameter and no limited type parameter in the list.
- -- RM E.2.3(14).
-
- if Present (Profile) then
- Param_Spec := First (Profile);
- while Present (Param_Spec) loop
- Param_Type := Etype (Defining_Identifier (Param_Spec));
- Type_Decl := Parent (Param_Type);
-
- if Ekind (Param_Type) = E_Anonymous_Access_Type then
-
- if K = N_Subprogram_Declaration then
- Error_Node := Param_Spec;
- end if;
-
- -- Report error only if declaration is in source program
-
- if Comes_From_Source
- (Defining_Entity (Specification (N)))
- then
- Error_Msg_N
- ("subprogram in 'R'C'I unit cannot have access parameter",
- Error_Node);
- end if;
-
- -- For a limited private type parameter, we check only the private
- -- declaration and ignore full type declaration, unless this is
- -- the only declaration for the type, e.g., as a limited record.
-
- elsif Is_Limited_Type (Param_Type)
- and then (Nkind (Type_Decl) = N_Private_Type_Declaration
- or else
- (Nkind (Type_Decl) = N_Full_Type_Declaration
- and then not (Has_Private_Declaration (Param_Type))
- and then Comes_From_Source (N)))
- then
- -- A limited parameter is legal only if user-specified Read and
- -- Write attributes exist for it. Second part of RM E.2.3 (14).
-
- if No (Full_View (Param_Type))
- and then Ekind (Param_Type) /= E_Record_Type
- then
- -- Type does not have completion yet, so if declared in
- -- the current RCI scope it is illegal, and will be flagged
- -- subsequently.
-
- return;
- end if;
-
- -- In Ada 95 the rules permit using a limited type that has
- -- user-specified Read and Write attributes that are specified
- -- in the private part of the package, whereas Ada 2005
- -- (AI-240) revises this to require the attributes to be
- -- "available" (implying that the attribute clauses must be
- -- visible to the RCI client). The Ada 95 rules violate the
- -- contract model for privacy, but we support both semantics
- -- for now for compatibility (note that ACATS test BXE2009
- -- checks a case that conforms to the Ada 95 rules but is
- -- illegal in Ada 2005). In the Ada 2005 case we check for the
- -- possibilities of visible TSS stream subprograms or explicit
- -- stream attribute definitions because the TSS subprograms
- -- can be hidden in the private part while the attribute
- -- definitions are still be available from the visible part.
-
- Base_Param_Type := Base_Type (Param_Type);
- Base_Under_Type := Base_Type (Underlying_Type
- (Base_Param_Type));
-
- if (Ada_Version < Ada_05
- and then
- (No (TSS (Base_Param_Type, TSS_Stream_Read))
- or else
- No (TSS (Base_Param_Type, TSS_Stream_Write)))
- and then
- (No (TSS (Base_Under_Type, TSS_Stream_Read))
- or else
- No (TSS (Base_Under_Type, TSS_Stream_Write))))
- or else
- (Ada_Version >= Ada_05
- and then
- (No (TSS (Base_Param_Type, TSS_Stream_Read))
- or else
- No (TSS (Base_Param_Type, TSS_Stream_Write))
- or else
- Is_Hidden (TSS (Base_Param_Type, TSS_Stream_Read))
- or else
- Is_Hidden (TSS (Base_Param_Type, TSS_Stream_Write)))
- and then
- (not Has_Stream_Attribute_Definition
- (Base_Param_Type, TSS_Stream_Read)
- or else
- not Has_Stream_Attribute_Definition
- (Base_Param_Type, TSS_Stream_Write)))
- then
- if K = N_Subprogram_Declaration then
- Error_Node := Param_Spec;
- end if;
-
- if Ada_Version >= Ada_05 then
- Error_Msg_N
- ("limited parameter in 'R'C'I unit "
- & "must have visible read/write attributes ",
- Error_Node);
- else
- Error_Msg_N
- ("limited parameter in 'R'C'I unit "
- & "must have read/write attributes ",
- Error_Node);
- end if;
- Explain_Limited_Type (Param_Type, Error_Node);
- end if;
-
- -- In Ada 95, any non-remote access type (or any type with a
- -- component of a non-remote access type) that is visible in an
- -- RCI unit comes from a Remote_Types or Remote_Call_Interface
- -- unit, and thus is already guaranteed to support external
- -- streaming. However in Ada 2005 we have to account for the case
- -- of named access types from declared pure units as well, which
- -- may or may not support external streaming, and so we need to
- -- perform a specific check for E.2.3(14/2) here.
-
- -- Note that if the declaration of the type itself is illegal, we
- -- do not perform this check since it might be a cascaded error.
-
- else
- if K = N_Subprogram_Declaration then
- Error_Node := Param_Spec;
- end if;
-
- if Missing_Read_Write_Attributes (Param_Type)
- and then not Error_Posted (Param_Type)
- then
- Error_Msg_N
- ("parameter containing non-remote access in 'R'C'I "
- & "subprogram must have visible "
- & "Read and Write attributes", Error_Node);
- end if;
- end if;
- Next (Param_Spec);
- end loop;
-
- -- No check on return type???
- end if;
- end Validate_RCI_Subprogram_Declaration;
-
- ----------------------------------------------------
- -- Validate_Remote_Access_Object_Type_Declaration --
- ----------------------------------------------------
-
- procedure Validate_Remote_Access_Object_Type_Declaration (T : Entity_Id) is
-
- function Is_Valid_Remote_Object_Type (E : Entity_Id) return Boolean;
- -- True if tagged type E is a valid candidate as the root type of the
- -- designated type for a RACW, i.e. a tagged limited private type, or a
- -- limited interface type, or a private extension of such a type.
-
- ---------------------------------
- -- Is_Valid_Remote_Object_Type --
- ---------------------------------
-
- function Is_Valid_Remote_Object_Type (E : Entity_Id) return Boolean is
- P : constant Node_Id := Parent (E);
-
- begin
- pragma Assert (Is_Tagged_Type (E));
-
- -- Simple case: a limited private type
-
- if Nkind (P) = N_Private_Type_Declaration
- and then Is_Limited_Record (E)
- then
- return True;
-
- -- A limited interface is not currently a legal ancestor for the
- -- designated type of an RACW type, because a type that implements
- -- such an interface need not be limited. However, the ARG seems to
- -- incline towards allowing an access to classwide limited interface
- -- type as a remote access type, as resolved in AI05-060. But note
- -- that the expansion circuitry for RACWs that designate classwide
- -- interfaces is not complete yet.
-
- elsif Is_Limited_Record (E) and then Is_Limited_Interface (E) then
- return True;
-
- -- A generic tagged limited type is a valid candidate. Limitedness
- -- will be checked again on the actual at instantiation point.
-
- elsif Nkind (P) = N_Formal_Type_Declaration
- and then Ekind (E) = E_Record_Type_With_Private
- and then Is_Generic_Type (E)
- and then Is_Limited_Record (E)
- then
- return True;
-
- -- A private extension declaration is a valid candidate if its parent
- -- type is.
-
- elsif Nkind (P) = N_Private_Extension_Declaration then
- return Is_Valid_Remote_Object_Type (Etype (E));
-
- else
- return False;
- end if;
- end Is_Valid_Remote_Object_Type;
-
- -- Local variables
-
- Direct_Designated_Type : Entity_Id;
- Desig_Type : Entity_Id;
-
- -- Start of processing for Validate_Remote_Access_Object_Type_Declaration
-
- begin
- -- We are called from Analyze_Type_Declaration, and the Nkind of the
- -- given node is N_Access_To_Object_Definition.
-
- if not Comes_From_Source (T)
- or else (not In_RCI_Declaration (Parent (T))
- and then not In_RT_Declaration)
- then
- return;
- end if;
-
- -- An access definition in the private part of a Remote Types package
- -- may be legal if it has user-defined Read and Write attributes. This
- -- will be checked at the end of the package spec processing.
-
- if In_RT_Declaration and then In_Private_Part (Scope (T)) then
- return;
- end if;
-
- -- Check RCI or RT unit type declaration. It may not contain the
- -- declaration of an access-to-object type unless it is a general access
- -- type that designates a class-wide limited private type. There are
- -- also constraints on the primitive subprograms of the class-wide type
- -- (RM E.2.2(14), see Validate_RACW_Primitives).
-
- if Ekind (T) /= E_General_Access_Type
- or else Ekind (Designated_Type (T)) /= E_Class_Wide_Type
- then
- if In_RCI_Declaration (Parent (T)) then
- Error_Msg_N
- ("error in access type in Remote_Call_Interface unit", T);
- else
- Error_Msg_N
- ("error in access type in Remote_Types unit", T);
- end if;
-
- Error_Msg_N ("\must be general access to class-wide type", T);
- return;
- end if;
-
- Direct_Designated_Type := Designated_Type (T);
- Desig_Type := Etype (Direct_Designated_Type);
-
- -- Why is the check below not in
- -- Validate_Remote_Access_To_Class_Wide_Type???
-
- if not Is_Valid_Remote_Object_Type (Desig_Type) then
- Error_Msg_N
- ("error in designated type of remote access to class-wide type", T);
- Error_Msg_N
- ("\must be tagged limited private or private extension", T);
- return;
- end if;
- end Validate_Remote_Access_Object_Type_Declaration;
-
- -----------------------------------------------
- -- Validate_Remote_Access_To_Class_Wide_Type --
- -----------------------------------------------
-
- procedure Validate_Remote_Access_To_Class_Wide_Type (N : Node_Id) is
- K : constant Node_Kind := Nkind (N);
- PK : constant Node_Kind := Nkind (Parent (N));
- E : Entity_Id;
-
- begin
- -- This subprogram enforces the checks in (RM E.2.2(8)) for certain uses
- -- of class-wide limited private types.
-
- -- Storage_Pool and Storage_Size are not defined for such types
- --
- -- The expected type of allocator must not be such a type.
-
- -- The actual parameter of generic instantiation must not be such a
- -- type if the formal parameter is of an access type.
-
- -- On entry, there are five cases
-
- -- 1. called from sem_attr Analyze_Attribute where attribute name is
- -- either Storage_Pool or Storage_Size.
-
- -- 2. called from exp_ch4 Expand_N_Allocator
-
- -- 3. called from sem_ch12 Analyze_Associations
-
- -- 4. called from sem_ch4 Analyze_Explicit_Dereference
-
- -- 5. called from sem_res Resolve_Actuals
-
- if K = N_Attribute_Reference then
- E := Etype (Prefix (N));
-
- if Is_Remote_Access_To_Class_Wide_Type (E) then
- Error_Msg_N ("incorrect attribute of remote operand", N);
- return;
- end if;
-
- elsif K = N_Allocator then
- E := Etype (N);
-
- if Is_Remote_Access_To_Class_Wide_Type (E) then
- Error_Msg_N ("incorrect expected remote type of allocator", N);
- return;
- end if;
-
- elsif K in N_Has_Entity then
- E := Entity (N);
-
- if Is_Remote_Access_To_Class_Wide_Type (E) then
- Error_Msg_N ("incorrect remote type generic actual", N);
- return;
- end if;
-
- -- This subprogram also enforces the checks in E.2.2(13). A value of
- -- such type must not be dereferenced unless as controlling operand of
- -- a dispatching call. Explicit dereferences not coming from source are
- -- exempted from this checking because the expander produces them in
- -- some cases (such as for tag checks on dispatching calls with multiple
- -- controlling operands). However we do check in the case of an implicit
- -- dereference that is expanded to an explicit dereference (hence the
- -- test of whether Original_Node (N) comes from source).
-
- elsif K = N_Explicit_Dereference
- and then Comes_From_Source (Original_Node (N))
- then
- E := Etype (Prefix (N));
-
- -- If the class-wide type is not a remote one, the restrictions
- -- do not apply.
-
- if not Is_Remote_Access_To_Class_Wide_Type (E) then
- return;
- end if;
-
- -- If we have a true dereference that comes from source and that
- -- is a controlling argument for a dispatching call, accept it.
-
- if Is_Actual_Parameter (N)
- and then Is_Controlling_Actual (N)
- then
- return;
- end if;
-
- -- If we are just within a procedure or function call and the
- -- dereference has not been analyzed, return because this procedure
- -- will be called again from sem_res Resolve_Actuals. The same can
- -- apply in the case of dereference that is the prefix of a selected
- -- component, which can be a call given in prefixed form.
-
- if (Is_Actual_Parameter (N)
- or else PK = N_Selected_Component)
- and then not Analyzed (N)
- then
- return;
- end if;
-
- -- We must allow expanded code to generate a reference to the tag of
- -- the designated object (may be either the actual tag, or the stub
- -- tag in the case of a remote object).
-
- if PK = N_Selected_Component
- and then Is_Tag (Entity (Selector_Name (Parent (N))))
- then
- return;
- end if;
-
- Error_Msg_N
- ("invalid dereference of a remote access-to-class-wide value", N);
- end if;
- end Validate_Remote_Access_To_Class_Wide_Type;
-
- ------------------------------------------
- -- Validate_Remote_Type_Type_Conversion --
- ------------------------------------------
-
- procedure Validate_Remote_Type_Type_Conversion (N : Node_Id) is
- S : constant Entity_Id := Etype (N);
- E : constant Entity_Id := Etype (Expression (N));
-
- begin
- -- This test is required in the case where a conversion appears inside a
- -- normal package, it does not necessarily have to be inside an RCI,
- -- Remote_Types unit (RM E.2.2(9,12)).
-
- if Is_Remote_Access_To_Subprogram_Type (E)
- and then not Is_Remote_Access_To_Subprogram_Type (S)
- then
- Error_Msg_N
- ("incorrect conversion of remote operand to local type", N);
- return;
-
- elsif not Is_Remote_Access_To_Subprogram_Type (E)
- and then Is_Remote_Access_To_Subprogram_Type (S)
- then
- Error_Msg_N
- ("incorrect conversion of local operand to remote type", N);
- return;
-
- elsif Is_Remote_Access_To_Class_Wide_Type (E)
- and then not Is_Remote_Access_To_Class_Wide_Type (S)
- then
- Error_Msg_N
- ("incorrect conversion of remote operand to local type", N);
- return;
- end if;
-
- -- If a local access type is converted into a RACW type, then the
- -- current unit has a pointer that may now be exported to another
- -- partition.
-
- if Is_Remote_Access_To_Class_Wide_Type (S)
- and then not Is_Remote_Access_To_Class_Wide_Type (E)
- then
- Set_Has_RACW (Current_Sem_Unit);
- end if;
- end Validate_Remote_Type_Type_Conversion;
-
- -------------------------------
- -- Validate_RT_RAT_Component --
- -------------------------------
-
- procedure Validate_RT_RAT_Component (N : Node_Id) is
- Spec : constant Node_Id := Specification (N);
- Name_U : constant Entity_Id := Defining_Entity (Spec);
- Typ : Entity_Id;
- U_Typ : Entity_Id;
- First_Priv_Ent : constant Entity_Id := First_Private_Entity (Name_U);
-
- begin
- if not Is_Remote_Types (Name_U) then
- return;
- end if;
-
- Typ := First_Entity (Name_U);
- while Present (Typ) and then Typ /= First_Priv_Ent loop
- U_Typ := Underlying_Type (Typ);
-
- if No (U_Typ) then
- U_Typ := Typ;
- end if;
-
- if Comes_From_Source (Typ) and then Is_Type (Typ) then
- if Missing_Read_Write_Attributes (Typ) then
- if Is_Non_Remote_Access_Type (Typ) then
- Error_Msg_N ("error in non-remote access type", U_Typ);
- else
- Error_Msg_N
- ("error in record type containing a component of a " &
- "non-remote access type", U_Typ);
- end if;
-
- if Ada_Version >= Ada_05 then
- Error_Msg_N
- ("\must have visible Read and Write attribute " &
- "definition clauses (RM E.2.2(8))", U_Typ);
- else
- Error_Msg_N
- ("\must have Read and Write attribute " &
- "definition clauses (RM E.2.2(8))", U_Typ);
- end if;
- end if;
- end if;
-
- Next_Entity (Typ);
- end loop;
- end Validate_RT_RAT_Component;
-
- -----------------------------------------
- -- Validate_SP_Access_Object_Type_Decl --
- -----------------------------------------
-
- procedure Validate_SP_Access_Object_Type_Decl (T : Entity_Id) is
- Direct_Designated_Type : Entity_Id;
-
- function Has_Entry_Declarations (E : Entity_Id) return Boolean;
- -- Return true if the protected type designated by T has
- -- entry declarations.
-
- ----------------------------
- -- Has_Entry_Declarations --
- ----------------------------
-
- function Has_Entry_Declarations (E : Entity_Id) return Boolean is
- Ety : Entity_Id;
-
- begin
- if Nkind (Parent (E)) = N_Protected_Type_Declaration then
- Ety := First_Entity (E);
- while Present (Ety) loop
- if Ekind (Ety) = E_Entry then
- return True;
- end if;
-
- Next_Entity (Ety);
- end loop;
- end if;
-
- return False;
- end Has_Entry_Declarations;
-
- -- Start of processing for Validate_SP_Access_Object_Type_Decl
-
- begin
- -- We are called from Sem_Ch3.Analyze_Type_Declaration, and the
- -- Nkind of the given entity is N_Access_To_Object_Definition.
-
- if not Comes_From_Source (T)
- or else not In_Shared_Passive_Unit
- or else In_Subprogram_Task_Protected_Unit
- then
- return;
- end if;
-
- -- Check Shared Passive unit. It should not contain the declaration
- -- of an access-to-object type whose designated type is a class-wide
- -- type, task type or protected type with entry (RM E.2.1(7)).
-
- Direct_Designated_Type := Designated_Type (T);
-
- if Ekind (Direct_Designated_Type) = E_Class_Wide_Type then
- Error_Msg_N
- ("invalid access-to-class-wide type in shared passive unit", T);
- return;
-
- elsif Ekind (Direct_Designated_Type) in Task_Kind then
- Error_Msg_N
- ("invalid access-to-task type in shared passive unit", T);
- return;
-
- elsif Ekind (Direct_Designated_Type) in Protected_Kind
- and then Has_Entry_Declarations (Direct_Designated_Type)
- then
- Error_Msg_N
- ("invalid access-to-protected type in shared passive unit", T);
- return;
- end if;
- end Validate_SP_Access_Object_Type_Decl;
-
- ---------------------------------
- -- Validate_Static_Object_Name --
- ---------------------------------
-
- procedure Validate_Static_Object_Name (N : Node_Id) is
- E : Entity_Id;
-
- function Is_Primary (N : Node_Id) return Boolean;
- -- Determine whether node is syntactically a primary in an expression
- -- This function should probably be somewhere else ???
- -- Also it does not do what it says, e.g if N is a binary operator
- -- whose parent is a binary operator, Is_Primary returns True ???
-
- ----------------
- -- Is_Primary --
- ----------------
-
- function Is_Primary (N : Node_Id) return Boolean is
- K : constant Node_Kind := Nkind (Parent (N));
-
- begin
- case K is
- when N_Op | N_Membership_Test =>
- return True;
-
- when N_Aggregate
- | N_Component_Association
- | N_Index_Or_Discriminant_Constraint =>
- return True;
-
- when N_Attribute_Reference =>
- return Attribute_Name (Parent (N)) /= Name_Address
- and then Attribute_Name (Parent (N)) /= Name_Access
- and then Attribute_Name (Parent (N)) /= Name_Unchecked_Access
- and then
- Attribute_Name (Parent (N)) /= Name_Unrestricted_Access;
-
- when N_Indexed_Component =>
- return (N /= Prefix (Parent (N))
- or else Is_Primary (Parent (N)));
-
- when N_Qualified_Expression | N_Type_Conversion =>
- return Is_Primary (Parent (N));
-
- when N_Assignment_Statement | N_Object_Declaration =>
- return (N = Expression (Parent (N)));
-
- when N_Selected_Component =>
- return Is_Primary (Parent (N));
-
- when others =>
- return False;
- end case;
- end Is_Primary;
-
- -- Start of processing for Validate_Static_Object_Name
-
- begin
- if not In_Preelaborated_Unit
- or else not Comes_From_Source (N)
- or else In_Subprogram_Or_Concurrent_Unit
- or else Ekind (Current_Scope) = E_Block
- then
- return;
-
- -- Filter out cases where primary is default in a component declaration,
- -- discriminant specification, or actual in a record type initialization
- -- call.
-
- -- Initialization call of internal types
-
- elsif Nkind (Parent (N)) = N_Procedure_Call_Statement then
-
- if Present (Parent (Parent (N)))
- and then Nkind (Parent (Parent (N))) = N_Freeze_Entity
- then
- return;
- end if;
-
- if Nkind (Name (Parent (N))) = N_Identifier
- and then not Comes_From_Source (Entity (Name (Parent (N))))
- then
- return;
- end if;
- end if;
-
- -- Error if the name is a primary in an expression. The parent must not
- -- be an operator, or a selected component or an indexed component that
- -- is itself a primary. Entities that are actuals do not need to be
- -- checked, because the call itself will be diagnosed.
-
- if Is_Primary (N)
- and then (not Inside_A_Generic
- or else Present (Enclosing_Generic_Body (N)))
- then
- if Ekind (Entity (N)) = E_Variable
- or else Ekind (Entity (N)) in Formal_Object_Kind
- then
- Flag_Non_Static_Expr
- ("non-static object name in preelaborated unit", N);
-
- -- We take the view that a constant defined in another preelaborated
- -- unit is preelaborable, even though it may have a private type and
- -- thus appear non-static in a client. This must be the intent of
- -- the language, but currently is an RM gap ???
-
- elsif Ekind (Entity (N)) = E_Constant
- and then not Is_Static_Expression (N)
- then
- E := Entity (N);
-
- if Is_Internal_File_Name (Unit_File_Name (Get_Source_Unit (N)))
- and then
- Enclosing_Lib_Unit_Node (N) /= Enclosing_Lib_Unit_Node (E)
- and then (Is_Preelaborated (Scope (E))
- or else Is_Pure (Scope (E))
- or else (Present (Renamed_Object (E))
- and then
- Is_Entity_Name (Renamed_Object (E))
- and then
- (Is_Preelaborated
- (Scope (Renamed_Object (E)))
- or else
- Is_Pure (Scope
- (Renamed_Object (E))))))
- then
- null;
-
- -- This is the error case
-
- else
- -- In GNAT mode, this is just a warning, to allow it to be
- -- judiciously turned off. Otherwise it is a real error.
-
- if GNAT_Mode then
- Error_Msg_N
- ("?non-static constant in preelaborated unit", N);
- else
- Flag_Non_Static_Expr
- ("non-static constant in preelaborated unit", N);
- end if;
- end if;
- end if;
- end if;
- end Validate_Static_Object_Name;
-
-end Sem_Cat;