blob: da56ce6ab722c8ccccbfa864e40585f4f96c4243 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 6 --
-- --
-- S p e c --
-- --
-- Copyright (C) 1992-2022, 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 Types; use Types;
package Sem_Ch6 is
type Conformance_Type is
(Type_Conformant, Mode_Conformant, Subtype_Conformant, Fully_Conformant);
pragma Ordered (Conformance_Type);
-- Conformance type used in conformance checks between specs and bodies,
-- and for overriding. The literals match the RM definitions of the
-- corresponding terms. This is an ordered type, since each conformance
-- type is stronger than the ones preceding it.
procedure Analyze_Abstract_Subprogram_Declaration (N : Node_Id);
procedure Analyze_Expression_Function (N : Node_Id);
procedure Analyze_Extended_Return_Statement (N : Node_Id);
procedure Analyze_Function_Call (N : Node_Id);
procedure Analyze_Operator_Symbol (N : Node_Id);
procedure Analyze_Parameter_Association (N : Node_Id);
procedure Analyze_Procedure_Call (N : Node_Id);
procedure Analyze_Return_When_Statement (N : Node_Id);
procedure Analyze_Simple_Return_Statement (N : Node_Id);
procedure Analyze_Subprogram_Declaration (N : Node_Id);
procedure Analyze_Subprogram_Body (N : Node_Id);
function Analyze_Subprogram_Specification (N : Node_Id) return Entity_Id;
-- Analyze subprogram specification in both subprogram declarations
-- and body declarations. Returns the defining entity for the
-- specification N.
function Can_Override_Operator (Subp : Entity_Id) return Boolean;
-- Returns true if Subp can override a predefined operator
procedure Check_Conventions (Typ : Entity_Id);
-- Ada 2005 (AI-430): Check that the conventions of all inherited and
-- overridden dispatching operations of type Typ are consistent with their
-- respective counterparts.
procedure Check_Delayed_Subprogram (Designator : Entity_Id);
-- Designator can be a E_Subprogram_Type, E_Procedure or E_Function. If a
-- type in its profile depends on a private type without a full
-- declaration, indicate that the subprogram or type is delayed.
procedure Check_Discriminant_Conformance
(N : Node_Id;
Prev : Entity_Id;
Prev_Loc : Node_Id);
-- Check that the discriminants of a full type N fully conform to the
-- discriminants of the corresponding partial view Prev. Prev_Loc indicates
-- the source location of the partial view, which may be different than
-- Prev in the case of private types.
procedure Check_Formal_Subprogram_Conformance
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty);
-- Check RM 6.3.1(17/3): the profile of a generic formal subprogram is not
-- subtype conformant with any other profile and post an error message if
-- either New_Id or Old_Id denotes a formal subprogram, with the flag being
-- placed on the Err_Loc node if it is specified, and on New_Id if not. See
-- also spec of Check_Fully_Conformant below for New_Id and Old_Id usage.
procedure Check_Fully_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty);
-- Check that two callable entities (subprograms, entries, literals)
-- are fully conformant, post error message if not (RM 6.3.1(17)) with
-- the flag being placed on the Err_Loc node if it is specified, and
-- on the appropriate component of the New_Id construct if not. Note:
-- when checking spec/body conformance, New_Id must be the body entity
-- and Old_Id is the spec entity (the code in the implementation relies
-- on this ordering, and in any case, this makes sense, since if flags
-- are to be placed on the construct, they clearly belong on the body.
procedure Check_Mode_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Get_Inst : Boolean := False);
-- Check that two callable entities (subprograms, entries, literals)
-- are mode conformant, post error message if not (RM 6.3.1(15)) with
-- the flag being placed on the Err_Loc node if it is specified, and
-- on the appropriate component of the New_Id construct if not. The
-- argument Get_Inst is set to True when this is a check against a
-- formal access-to-subprogram type, indicating that mapping of types
-- is needed.
procedure Check_Overriding_Indicator
(Subp : Entity_Id;
Overridden_Subp : Entity_Id;
Is_Primitive : Boolean);
-- Verify the consistency of an overriding_indicator given for subprogram
-- declaration, body, renaming, or instantiation. Overridden_Subp is set
-- if the scope where we are introducing the subprogram contains a
-- type-conformant subprogram that becomes hidden by the new subprogram.
-- Is_Primitive indicates whether the subprogram is primitive.
procedure Check_Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty;
Skip_Controlling_Formals : Boolean := False;
Get_Inst : Boolean := False);
-- Check that two callable entities (subprograms, entries, literals)
-- are subtype conformant, post error message if not (RM 6.3.1(16)),
-- the flag being placed on the Err_Loc node if it is specified, and
-- on the appropriate component of the New_Id construct if not.
-- Skip_Controlling_Formals is True when checking the conformance of
-- a subprogram that implements an interface operation. In that case,
-- only the non-controlling formals can (and must) be examined. The
-- argument Get_Inst is set to True when this is a check against a
-- formal access-to-subprogram type, indicating that mapping of types
-- is needed.
procedure Check_Synchronized_Overriding
(Def_Id : Entity_Id;
Overridden_Subp : out Entity_Id);
-- First determine if Def_Id is an entry or a subprogram either defined in
-- the scope of a task or protected type, or that is a primitive of such
-- a type. Check whether Def_Id overrides a subprogram of an interface
-- implemented by the synchronized type, returning the overridden entity
-- or Empty.
procedure Check_Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Err_Loc : Node_Id := Empty);
-- Check that two callable entities (subprograms, entries, literals)
-- are type conformant, post error message if not (RM 6.3.1(14)) with
-- the flag being placed on the Err_Loc node if it is specified, and
-- on the appropriate component of the New_Id construct if not.
function Conforming_Types
(T1 : Entity_Id;
T2 : Entity_Id;
Ctype : Conformance_Type;
Get_Inst : Boolean := False) return Boolean;
-- Check that the types of two formal parameters are conforming. In most
-- cases this is just a name comparison, but within an instance it involves
-- generic actual types, and in the presence of anonymous access types
-- it must examine the designated types. The argument Get_Inst is set to
-- True when this is a check against a formal access-to-subprogram type,
-- indicating that mapping of types is needed.
procedure Create_Extra_Formals (E : Entity_Id);
-- For each parameter of a subprogram or entry that requires an additional
-- formal (such as for access parameters and indefinite discriminated
-- parameters), creates the appropriate formal and attach it to its
-- associated parameter. Each extra formal will also be appended to
-- the end of Subp's parameter list (with each subsequent extra formal
-- being attached to the preceding extra formal).
function Find_Corresponding_Spec
(N : Node_Id;
Post_Error : Boolean := True) return Entity_Id;
-- Use the subprogram specification in the body to retrieve the previous
-- subprogram declaration, if any.
function Fully_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
-- Determine whether two callable entities (subprograms, entries,
-- literals) are fully conformant (RM 6.3.1(17))
function Fully_Conformant_Expressions
(Given_E1 : Node_Id;
Given_E2 : Node_Id;
Report : Boolean := False) return Boolean;
-- Determines if two (non-empty) expressions are fully conformant
-- as defined by (RM 6.3.1(18-21))
function Fully_Conformant_Discrete_Subtypes
(Given_S1 : Node_Id;
Given_S2 : Node_Id) return Boolean;
-- Determines if two subtype definitions are fully conformant. Used
-- for entry family conformance checks (RM 6.3.1 (24)).
procedure Install_Entity (E : Entity_Id);
-- Place a single entity on the visibility chain
procedure Install_Formals (Id : Entity_Id);
-- On entry to a subprogram body, make the formals visible. Note that
-- simply placing the subprogram on the scope stack is not sufficient:
-- the formals must become the current entities for their names. This
-- procedure is also used to get visibility to the formals when analyzing
-- preconditions and postconditions appearing in the spec.
function Is_Interface_Conformant
(Tagged_Type : Entity_Id;
Iface_Prim : Entity_Id;
Prim : Entity_Id) return Boolean;
-- Returns true if both primitives have a matching name (including support
-- for names of inherited private primitives --which have suffix 'P'), they
-- are type conformant, and Prim is defined in the scope of Tagged_Type.
-- Special management is done for functions returning interfaces.
procedure List_Inherited_Pre_Post_Aspects (E : Entity_Id);
-- E is the entity for a subprogram or generic subprogram spec. This call
-- lists all inherited Pre/Post aspects if List_Inherited_Pre_Post is True.
procedure May_Need_Actuals (Fun : Entity_Id);
-- Flag functions that can be called without parameters, i.e. those that
-- have no parameters, or those for which defaults exist for all parameters
-- Used for subprogram declarations and for access subprogram declarations,
-- where they apply to the anonymous designated type. On return the flag
-- Set_Needs_No_Actuals is set appropriately in Fun.
function Mode_Conformant (New_Id, Old_Id : Entity_Id) return Boolean;
-- Determine whether two callable entities (subprograms, entries,
-- literals) are mode conformant (RM 6.3.1(15))
procedure New_Overloaded_Entity
(S : Entity_Id;
Derived_Type : Entity_Id := Empty);
-- Process new overloaded entity. Overloaded entities are created by
-- enumeration type declarations, subprogram specifications, entry
-- declarations, and (implicitly) by type derivations. If Derived_Type
-- is non-empty then this is a subprogram derived for that type.
procedure Process_Formals (T : List_Id; Related_Nod : Node_Id);
-- Enter the formals in the scope of the subprogram or entry, and
-- analyze default expressions if any. The implicit types created for
-- access parameter are attached to the Related_Nod which comes from the
-- context.
procedure Reference_Body_Formals (Spec : Entity_Id; Bod : Entity_Id);
-- If there is a separate spec for a subprogram or generic subprogram, the
-- formals of the body are treated as references to the corresponding
-- formals of the spec. This reference does not count as an actual use of
-- the formal, in order to diagnose formals that are unused in the body.
-- This procedure is also used in renaming_as_body declarations, where
-- the formals of the specification must be treated as body formals that
-- correspond to the previous subprogram declaration, and not as new
-- entities with their defining entry in the cross-reference information.
procedure Set_Actual_Subtypes (N : Node_Id; Subp : Entity_Id);
-- If the formals of a subprogram are unconstrained, build a subtype
-- declaration that uses the bounds or discriminants of the actual to
-- construct an actual subtype for them. This is an optimization that
-- is done only in some cases where the actual subtype cannot change
-- during execution of the subprogram. By setting the actual subtype
-- once, we avoid recomputing it unnecessarily.
procedure Set_Formal_Mode (Formal_Id : Entity_Id);
-- Set proper Ekind to reflect formal mode (in, out, in out)
function Subtype_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean;
-- Determine whether two callable entities (subprograms, entries, literals)
-- are subtype conformant (RM 6.3.1(16)). Skip_Controlling_Formals is True
-- when checking the conformance of a subprogram that implements an
-- interface operation. In that case, only the non-controlling formals
-- can (and must) be examined.
function Type_Conformant
(New_Id : Entity_Id;
Old_Id : Entity_Id;
Skip_Controlling_Formals : Boolean := False) return Boolean;
-- Determine whether two callable entities (subprograms, entries, literals)
-- are type conformant (RM 6.3.1(14)). Skip_Controlling_Formals is True
-- when checking the conformance of a subprogram that implements an
-- interface operation. In that case, only the non-controlling formals
-- can (and must) be examined.
procedure Valid_Operator_Definition (Designator : Entity_Id);
-- Verify that an operator definition has the proper number of formals
end Sem_Ch6;