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-- --
-- --
-- S E M _ C H 3 --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2018, 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 --
-- 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 Nlists; use Nlists;
with Types; use Types;
package Sem_Ch3 is
procedure Analyze_Component_Declaration (N : Node_Id);
procedure Analyze_Full_Type_Declaration (N : Node_Id);
procedure Analyze_Incomplete_Type_Decl (N : Node_Id);
procedure Analyze_Itype_Reference (N : Node_Id);
procedure Analyze_Number_Declaration (N : Node_Id);
procedure Analyze_Object_Declaration (N : Node_Id);
procedure Analyze_Others_Choice (N : Node_Id);
procedure Analyze_Private_Extension_Declaration (N : Node_Id);
procedure Analyze_Subtype_Indication (N : Node_Id);
procedure Analyze_Variant_Part (N : Node_Id);
procedure Analyze_Subtype_Declaration
(N : Node_Id;
Skip : Boolean := False);
-- Called to analyze a subtype declaration. The parameter Skip is used for
-- Ada 2005 (AI-412). We set to True in order to avoid reentering the
-- defining identifier of N when analyzing a rewritten incomplete subtype
-- declaration.
function Access_Definition
(Related_Nod : Node_Id;
N : Node_Id) return Entity_Id;
-- An access definition defines a general access type for a formal
-- parameter. The procedure is called when processing formals, when the
-- current scope is the subprogram. The Implicit type is attached to the
-- Related_Nod put into the enclosing scope, so that the only entities
-- defined in the spec are the formals themselves.
procedure Access_Subprogram_Declaration
(T_Name : Entity_Id;
T_Def : Node_Id);
-- The subprogram specification yields the signature of an implicit
-- type, whose Ekind is Access_Subprogram_Type. This implicit type is the
-- designated type of the declared access type. In subprogram calls, the
-- signature of the implicit type works like the profile of a regular
-- subprogram.
procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id);
-- Add to the list of primitives of Tagged_Type the internal entities
-- associated with covered interface primitives. These entities link the
-- interface primitives with the tagged type primitives that cover them.
procedure Analyze_Declarations (L : List_Id);
-- Called to analyze a list of declarations (in what context ???). Also
-- performs necessary freezing actions (more description needed ???)
procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id);
-- Analyze an interface declaration or a formal interface declaration
procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id);
-- Process an array type declaration. If the array is constrained, we
-- create an implicit parent array type, with the same index types and
-- component type.
procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id);
-- Process an access type declaration
procedure Build_Itype_Reference (Ityp : Entity_Id; Nod : Node_Id);
-- Create a reference to an internal type, for use by Gigi. The back-end
-- elaborates itypes on demand, i.e. when their first use is seen. This can
-- lead to scope anomalies if the first use is within a scope that is
-- nested within the scope that contains the point of definition of the
-- itype. The Itype_Reference node forces the elaboration of the itype
-- in the proper scope. The node is inserted after Nod, which is the
-- enclosing declaration that generated Ityp.
-- A related mechanism is used during expansion, for itypes created in
-- branches of conditionals. See Ensure_Defined in exp_util. Could both
-- mechanisms be merged ???
procedure Check_Abstract_Overriding (T : Entity_Id);
-- Check that all abstract subprograms inherited from T's parent type have
-- been overridden as required, and that nonabstract subprograms have not
-- been incorrectly overridden with an abstract subprogram.
procedure Check_Aliased_Component_Types (T : Entity_Id);
-- Given an array type or record type T, check that if the type is
-- nonlimited, then the nominal subtype of any components of T that
-- have discriminants must be constrained.
procedure Check_Completion (Body_Id : Node_Id := Empty);
-- At the end of a declarative part, verify that all entities that require
-- completion have received one. If Body_Id is absent, the error indicating
-- a missing completion is placed on the declaration that needs completion.
-- If Body_Id is present, it is the defining identifier of a package body,
-- and errors are posted on that node, rather than on the declarations that
-- require completion in the package declaration.
procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id);
-- Check that components of imported CPP type T do not have default
-- expressions because the constructor (if any) is on the C++ side.
procedure Derive_Subprogram
(New_Subp : out Entity_Id;
Parent_Subp : Entity_Id;
Derived_Type : Entity_Id;
Parent_Type : Entity_Id;
Actual_Subp : Entity_Id := Empty);
-- Derive the subprogram Parent_Subp from Parent_Type, and replace the
-- subsidiary subtypes with the derived type to build the specification of
-- the inherited subprogram (returned in New_Subp). For tagged types, the
-- derived subprogram is aliased to that of the actual (in the case where
-- Actual_Subp is nonempty) rather than to the corresponding subprogram of
-- the parent type.
procedure Derive_Subprograms
(Parent_Type : Entity_Id;
Derived_Type : Entity_Id;
Generic_Actual : Entity_Id := Empty);
-- To complete type derivation, collect/retrieve the primitive operations
-- of the parent type, and replace the subsidiary subtypes with the derived
-- type, to build the specs of the inherited ops. For generic actuals, the
-- mapping of the primitive operations to those of the parent type is also
-- done by rederiving the operations within the instance. For tagged types,
-- the derived subprograms are aliased to those of the actual, not those of
-- the ancestor.
-- Note: one might expect this to be private to the package body, but there
-- is one rather unusual usage in package Exp_Dist.
function Find_Hidden_Interface
(Src : Elist_Id;
Dest : Elist_Id) return Entity_Id;
-- Ada 2005: Determine whether the interfaces in list Src are all present
-- in the list Dest. Return the first differing interface, or Empty
-- otherwise.
function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
-- Given a subtype indication S (which is really an N_Subtype_Indication
-- node or a plain N_Identifier), find the type of the subtype mark.
function Find_Type_Name (N : Node_Id) return Entity_Id;
-- Enter the identifier in a type definition, or find the entity already
-- declared, in the case of the full declaration of an incomplete or
-- private type. If the previous declaration is tagged then the class-wide
-- entity is propagated to the identifier to prevent multiple incompatible
-- class-wide types that may be created for self-referential anonymous
-- access components.
function Get_Discriminant_Value
(Discriminant : Entity_Id;
Typ_For_Constraint : Entity_Id;
Constraint : Elist_Id) return Node_Id;
-- Given a discriminant somewhere in the Typ_For_Constraint tree and a
-- Constraint, return the value of that discriminant.
function Is_Null_Extension (T : Entity_Id) return Boolean;
-- Returns True if the tagged type T has an N_Full_Type_Declaration that
-- is a null extension, meaning that it has an extension part without any
-- components and does not have a known discriminant part.
function Is_Visible_Component
(C : Entity_Id;
N : Node_Id := Empty) return Boolean;
-- Determines if a record component C is visible in the present context.
-- Note that even though component C could appear in the entity chain of a
-- record type, C may not be visible in the current context. For instance,
-- C may be a component inherited in the full view of a private extension
-- which is not visible in the current context.
-- If present, N is the selected component of which C is the selector. If
-- the prefix of N is a type conversion inserted for a discriminant check,
-- C is automatically visible.
procedure Make_Index
(N : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix_Index : Nat := 1;
In_Iter_Schm : Boolean := False);
-- Process an index that is given in an array declaration, an entry
-- family declaration or a loop iteration. The index is given by an index
-- declaration (a 'box'), or by a discrete range. The later can be the name
-- of a discrete type, or a subtype indication.
-- Related_Nod is the node where the potential generated implicit types
-- will be inserted. The next last parameters are used for creating the
-- name. In_Iter_Schm is True if Make_Index is called on the discrete
-- subtype definition in an iteration scheme.
procedure Make_Class_Wide_Type (T : Entity_Id);
-- A Class_Wide_Type is created for each tagged type definition. The
-- attributes of a class-wide type are inherited from those of the type T.
-- If T is introduced by a private declaration, the corresponding class
-- wide type is created at the same time, and therefore there is a private
-- and a full declaration for the class-wide type as well.
function OK_For_Limited_Init_In_05
(Typ : Entity_Id;
Exp : Node_Id) return Boolean;
-- Presuming Exp is an expression of an inherently limited type Typ,
-- returns True if the expression is allowed in an initialization context
-- by the rules of Ada 2005. We use the rule in RM-7.5(2.1/2), " is an
-- aggregate, a function_call, or a parenthesized expression or qualified
-- expression whose operand is permitted...". Note that in Ada 95 mode,
-- we sometimes wish to give warnings based on whether the program _would_
-- be legal in Ada 2005. Note that Exp must already have been resolved,
-- so we can know whether it's a function call (as opposed to an indexed
-- component, for example). In the case where Typ is a limited interface's
-- class-wide type, then the expression is allowed to be of any kind if its
-- type is a nonlimited descendant of the interface.
function OK_For_Limited_Init
(Typ : Entity_Id;
Exp : Node_Id) return Boolean;
-- Always False in Ada 95 mode. Equivalent to OK_For_Limited_Init_In_05 in
-- Ada 2005 mode.
procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id);
-- Default and per object expressions do not freeze their components, and
-- must be analyzed and resolved accordingly. The analysis is done by
-- calling the Preanalyze_And_Resolve routine and setting the global
-- In_Default_Expression flag. See the documentation section entitled
-- "Handling of Default and Per-Object Expressions" in for full
-- details. N is the expression to be analyzed, T is the expected type.
-- This mechanism is also used for aspect specifications that have an
-- expression parameter that needs similar preanalysis.
procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id);
-- Wrapper on Preanalyze_Spec_Expression for assertion expressions, so that
-- In_Assertion_Expr can be properly adjusted.
procedure Preanalyze_Default_Expression (N : Node_Id; T : Entity_Id);
-- Wrapper on Preanalyze_Spec_Expression for default expressions, so that
-- In_Default_Expr can be properly adjusted.
procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id);
-- Process some semantic actions when the full view of a private type is
-- encountered and analyzed. The first action is to create the full views
-- of the dependant private subtypes. The second action is to recopy the
-- primitive operations of the private view (in the tagged case).
-- N is the N_Full_Type_Declaration node.
-- Full_T is the full view of the type whose full declaration is in N.
-- Priv_T is the private view of the type whose full declaration is in N.
procedure Process_Range_Expr_In_Decl
(R : Node_Id;
T : Entity_Id;
Subtyp : Entity_Id := Empty;
Check_List : List_Id := Empty_List;
R_Check_Off : Boolean := False;
In_Iter_Schm : Boolean := False);
-- Process a range expression that appears in a declaration context. The
-- range is analyzed and resolved with the base type of the given type, and
-- an appropriate check for expressions in non-static contexts made on the
-- bounds. R is analyzed and resolved using T, so the caller should if
-- necessary link R into the tree before the call, and in particular in the
-- case of a subtype declaration, it is appropriate to set the parent
-- pointer of R so that the types get properly frozen. Check_List is used
-- when the subprogram is called from Build_Record_Init_Proc and is used to
-- return a set of constraint checking statements generated by the Checks
-- package. R_Check_Off is set to True when the call to Range_Check is to
-- be skipped. In_Iter_Schm is True if Process_Range_Expr_In_Decl is called
-- on the discrete subtype definition in an iteration scheme.
-- If Subtyp is given, then the range is for the named subtype Subtyp, and
-- in this case the bounds are captured if necessary using this name.
function Process_Subtype
(S : Node_Id;
Related_Nod : Node_Id;
Related_Id : Entity_Id := Empty;
Suffix : Character := ' ') return Entity_Id;
-- Process a subtype indication S and return corresponding entity.
-- Related_Nod is the node where the potential generated implicit types
-- will be inserted. The Related_Id and Suffix parameters are used to
-- build the associated Implicit type name.
procedure Process_Discriminants
(N : Node_Id;
Prev : Entity_Id := Empty);
-- Process the discriminants contained in an N_Full_Type_Declaration or
-- N_Incomplete_Type_Decl node N. If the declaration is a completion, Prev
-- is entity on the partial view, on which references are posted. However,
-- note that Process_Discriminants is called for a completion only if
-- partial view had no discriminants (else we just check conformance
-- between the two views and do not call Process_Discriminants again
-- for the completion).
function Replace_Anonymous_Access_To_Protected_Subprogram
(N : Node_Id) return Entity_Id;
-- Ada 2005 (AI-254): Create and decorate an internal full type declaration
-- for an anonymous access to protected subprogram. For a record component
-- declaration, the type is created in the enclosing scope, for an array
-- type declaration or an object declaration it is simply placed ahead of
-- this declaration.
procedure Set_Completion_Referenced (E : Entity_Id);
-- If E is the completion of a private or incomplete type declaration,
-- or the completion of a deferred constant declaration, mark the entity
-- as referenced. Warnings on unused entities, if needed, go on the
-- partial view.
end Sem_Ch3;