Google Git
Sign in
gnu / gcc / 926d9947847a0683cf34de6fc231209747576088 / . / gcc / ada / sem_ch8.adb
blob: ab9ee00dc68a301353a841d73f852ed36bbb9a93 [file] [log] [blame]
------------------------------------------------------------------------------
-- --
-- GNAT COMPILER COMPONENTS --
-- --
-- S E M _ C H 8 --
-- --
-- B o d y --
-- --
-- Copyright (C) 1992-2015, 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 Exp_Tss; use Exp_Tss;
with Exp_Util; use Exp_Util;
with Fname; use Fname;
with Freeze; use Freeze;
with Ghost; use Ghost;
with Impunit; use Impunit;
with Lib; use Lib;
with Lib.Load; use Lib.Load;
with Lib.Xref; use Lib.Xref;
with Namet; use Namet;
with Namet.Sp; use Namet.Sp;
with Nlists; use Nlists;
with Nmake; use Nmake;
with Opt; use Opt;
with Output; use Output;
with Restrict; use Restrict;
with Rident; use Rident;
with Rtsfind; use Rtsfind;
with Sem; use Sem;
with Sem_Aux; use Sem_Aux;
with Sem_Cat; use Sem_Cat;
with Sem_Ch3; use Sem_Ch3;
with Sem_Ch4; use Sem_Ch4;
with Sem_Ch6; use Sem_Ch6;
with Sem_Ch12; use Sem_Ch12;
with Sem_Ch13; use Sem_Ch13;
with Sem_Dim; use Sem_Dim;
with Sem_Disp; use Sem_Disp;
with Sem_Dist; use Sem_Dist;
with Sem_Eval; use Sem_Eval;
with Sem_Res; use Sem_Res;
with Sem_Util; use Sem_Util;
with Sem_Type; use Sem_Type;
with Stand; use Stand;
with Sinfo; use Sinfo;
with Sinfo.CN; use Sinfo.CN;
with Snames; use Snames;
with Style; use Style;
with Table;
with Targparm; use Targparm;
with Tbuild; use Tbuild;
with Uintp; use Uintp;
package body Sem_Ch8 is
------------------------------------
-- Visibility and Name Resolution --
------------------------------------
-- This package handles name resolution and the collection of possible
-- interpretations for overloaded names, prior to overload resolution.
-- Name resolution is the process that establishes a mapping between source
-- identifiers and the entities they denote at each point in the program.
-- Each entity is represented by a defining occurrence. Each identifier
-- that denotes an entity points to the corresponding defining occurrence.
-- This is the entity of the applied occurrence. Each occurrence holds
-- an index into the names table, where source identifiers are stored.
-- Each entry in the names table for an identifier or designator uses the
-- Info pointer to hold a link to the currently visible entity that has
-- this name (see subprograms Get_Name_Entity_Id and Set_Name_Entity_Id
-- in package Sem_Util). The visibility is initialized at the beginning of
-- semantic processing to make entities in package Standard immediately
-- visible. The visibility table is used in a more subtle way when
-- compiling subunits (see below).
-- Entities that have the same name (i.e. homonyms) are chained. In the
-- case of overloaded entities, this chain holds all the possible meanings
-- of a given identifier. The process of overload resolution uses type
-- information to select from this chain the unique meaning of a given
-- identifier.
-- Entities are also chained in their scope, through the Next_Entity link.
-- As a consequence, the name space is organized as a sparse matrix, where
-- each row corresponds to a scope, and each column to a source identifier.
-- Open scopes, that is to say scopes currently being compiled, have their
-- corresponding rows of entities in order, innermost scope first.
-- The scopes of packages that are mentioned in context clauses appear in
-- no particular order, interspersed among open scopes. This is because
-- in the course of analyzing the context of a compilation, a package
-- declaration is first an open scope, and subsequently an element of the
-- context. If subunits or child units are present, a parent unit may
-- appear under various guises at various times in the compilation.
-- When the compilation of the innermost scope is complete, the entities
-- defined therein are no longer visible. If the scope is not a package
-- declaration, these entities are never visible subsequently, and can be
-- removed from visibility chains. If the scope is a package declaration,
-- its visible declarations may still be accessible. Therefore the entities
-- defined in such a scope are left on the visibility chains, and only
-- their visibility (immediately visibility or potential use-visibility)
-- is affected.
-- The ordering of homonyms on their chain does not necessarily follow
-- the order of their corresponding scopes on the scope stack. For
-- example, if package P and the enclosing scope both contain entities
-- named E, then when compiling the package body the chain for E will
-- hold the global entity first, and the local one (corresponding to
-- the current inner scope) next. As a result, name resolution routines
-- do not assume any relative ordering of the homonym chains, either
-- for scope nesting or to order of appearance of context clauses.
-- When compiling a child unit, entities in the parent scope are always
-- immediately visible. When compiling the body of a child unit, private
-- entities in the parent must also be made immediately visible. There
-- are separate routines to make the visible and private declarations
-- visible at various times (see package Sem_Ch7).
-- +--------+ +-----+
-- | In use |-------->| EU1 |-------------------------->
-- +--------+ +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Stand. |---------------->| ES1 |--------------->| ES2 |--->
-- +--------+ +-----+ +-----+
-- | |
-- +---------+ | +-----+
-- | with'ed |------------------------------>| EW2 |--->
-- +---------+ | +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Scope2 |---------------->| E12 |--------------->| E22 |--->
-- +--------+ +-----+ +-----+
-- | |
-- +--------+ +-----+ +-----+
-- | Scope1 |---------------->| E11 |--------------->| E12 |--->
-- +--------+ +-----+ +-----+
-- ^ | |
-- | | |
-- | +---------+ | |
-- | | with'ed |----------------------------------------->
-- | +---------+ | |
-- | | |
-- Scope stack | |
-- (innermost first) | |
-- +----------------------------+
-- Names table => | Id1 | | | | Id2 |
-- +----------------------------+
-- Name resolution must deal with several syntactic forms: simple names,
-- qualified names, indexed names, and various forms of calls.
-- Each identifier points to an entry in the names table. The resolution
-- of a simple name consists in traversing the homonym chain, starting
-- from the names table. If an entry is immediately visible, it is the one
-- designated by the identifier. If only potentially use-visible entities
-- are on the chain, we must verify that they do not hide each other. If
-- the entity we find is overloadable, we collect all other overloadable
-- entities on the chain as long as they are not hidden.
--
-- To resolve expanded names, we must find the entity at the intersection
-- of the entity chain for the scope (the prefix) and the homonym chain
-- for the selector. In general, homonym chains will be much shorter than
-- entity chains, so it is preferable to start from the names table as
-- well. If the entity found is overloadable, we must collect all other
-- interpretations that are defined in the scope denoted by the prefix.
-- For records, protected types, and tasks, their local entities are
-- removed from visibility chains on exit from the corresponding scope.
-- From the outside, these entities are always accessed by selected
-- notation, and the entity chain for the record type, protected type,
-- etc. is traversed sequentially in order to find the designated entity.
-- The discriminants of a type and the operations of a protected type or
-- task are unchained on exit from the first view of the type, (such as
-- a private or incomplete type declaration, or a protected type speci-
-- fication) and re-chained when compiling the second view.
-- In the case of operators, we do not make operators on derived types
-- explicit. As a result, the notation P."+" may denote either a user-
-- defined function with name "+", or else an implicit declaration of the
-- operator "+" in package P. The resolution of expanded names always
-- tries to resolve an operator name as such an implicitly defined entity,
-- in addition to looking for explicit declarations.
-- All forms of names that denote entities (simple names, expanded names,
-- character literals in some cases) have a Entity attribute, which
-- identifies the entity denoted by the name.
---------------------
-- The Scope Stack --
---------------------
-- The Scope stack keeps track of the scopes currently been compiled.
-- Every entity that contains declarations (including records) is placed
-- on the scope stack while it is being processed, and removed at the end.
-- Whenever a non-package scope is exited, the entities defined therein
-- are removed from the visibility table, so that entities in outer scopes
-- become visible (see previous description). On entry to Sem, the scope
-- stack only contains the package Standard. As usual, subunits complicate
-- this picture ever so slightly.
-- The Rtsfind mechanism can force a call to Semantics while another
-- compilation is in progress. The unit retrieved by Rtsfind must be
-- compiled in its own context, and has no access to the visibility of
-- the unit currently being compiled. The procedures Save_Scope_Stack and
-- Restore_Scope_Stack make entities in current open scopes invisible
-- before compiling the retrieved unit, and restore the compilation
-- environment afterwards.
------------------------
-- Compiling subunits --
------------------------
-- Subunits must be compiled in the environment of the corresponding stub,
-- that is to say with the same visibility into the parent (and its
-- context) that is available at the point of the stub declaration, but
-- with the additional visibility provided by the context clause of the
-- subunit itself. As a result, compilation of a subunit forces compilation
-- of the parent (see description in lib-). At the point of the stub
-- declaration, Analyze is called recursively to compile the proper body of
-- the subunit, but without reinitializing the names table, nor the scope
-- stack (i.e. standard is not pushed on the stack). In this fashion the
-- context of the subunit is added to the context of the parent, and the
-- subunit is compiled in the correct environment. Note that in the course
-- of processing the context of a subunit, Standard will appear twice on
-- the scope stack: once for the parent of the subunit, and once for the
-- unit in the context clause being compiled. However, the two sets of
-- entities are not linked by homonym chains, so that the compilation of
-- any context unit happens in a fresh visibility environment.
-------------------------------
-- Processing of USE Clauses --
-------------------------------
-- Every defining occurrence has a flag indicating if it is potentially use
-- visible. Resolution of simple names examines this flag. The processing
-- of use clauses consists in setting this flag on all visible entities
-- defined in the corresponding package. On exit from the scope of the use
-- clause, the corresponding flag must be reset. However, a package may
-- appear in several nested use clauses (pathological but legal, alas)
-- which forces us to use a slightly more involved scheme:
-- a) The defining occurrence for a package holds a flag -In_Use- to
-- indicate that it is currently in the scope of a use clause. If a
-- redundant use clause is encountered, then the corresponding occurrence
-- of the package name is flagged -Redundant_Use-.
-- b) On exit from a scope, the use clauses in its declarative part are
-- scanned. The visibility flag is reset in all entities declared in
-- package named in a use clause, as long as the package is not flagged
-- as being in a redundant use clause (in which case the outer use
-- clause is still in effect, and the direct visibility of its entities
-- must be retained).
-- Note that entities are not removed from their homonym chains on exit
-- from the package specification. A subsequent use clause does not need
-- to rechain the visible entities, but only to establish their direct
-- visibility.
-----------------------------------
-- Handling private declarations --
-----------------------------------
-- The principle that each entity has a single defining occurrence clashes
-- with the presence of two separate definitions for private types: the
-- first is the private type declaration, and second is the full type
-- declaration. It is important that all references to the type point to
-- the same defining occurrence, namely the first one. To enforce the two
-- separate views of the entity, the corresponding information is swapped
-- between the two declarations. Outside of the package, the defining
-- occurrence only contains the private declaration information, while in
-- the private part and the body of the package the defining occurrence
-- contains the full declaration. To simplify the swap, the defining
-- occurrence that currently holds the private declaration points to the
-- full declaration. During semantic processing the defining occurrence
-- also points to a list of private dependents, that is to say access types
-- or composite types whose designated types or component types are
-- subtypes or derived types of the private type in question. After the
-- full declaration has been seen, the private dependents are updated to
-- indicate that they have full definitions.
------------------------------------
-- Handling of Undefined Messages --
------------------------------------
-- In normal mode, only the first use of an undefined identifier generates
-- a message. The table Urefs is used to record error messages that have
-- been issued so that second and subsequent ones do not generate further
-- messages. However, the second reference causes text to be added to the
-- original undefined message noting "(more references follow)". The
-- full error list option (-gnatf) forces messages to be generated for
-- every reference and disconnects the use of this table.
type Uref_Entry is record
Node : Node_Id;
-- Node for identifier for which original message was posted. The
-- Chars field of this identifier is used to detect later references
-- to the same identifier.
Err : Error_Msg_Id;
-- Records error message Id of original undefined message. Reset to
-- No_Error_Msg after the second occurrence, where it is used to add
-- text to the original message as described above.
Nvis : Boolean;
-- Set if the message is not visible rather than undefined
Loc : Source_Ptr;
-- Records location of error message. Used to make sure that we do
-- not consider a, b : undefined as two separate instances, which
-- would otherwise happen, since the parser converts this sequence
-- to a : undefined; b : undefined.
end record;
package Urefs is new Table.Table (
Table_Component_Type => Uref_Entry,
Table_Index_Type => Nat,
Table_Low_Bound => 1,
Table_Initial => 10,
Table_Increment => 100,
Table_Name => "Urefs");
Candidate_Renaming : Entity_Id;
-- Holds a candidate interpretation that appears in a subprogram renaming
-- declaration and does not match the given specification, but matches at
-- least on the first formal. Allows better error message when given
-- specification omits defaulted parameters, a common error.
-----------------------
-- Local Subprograms --
-----------------------
procedure Analyze_Generic_Renaming
(N : Node_Id;
K : Entity_Kind);
-- Common processing for all three kinds of generic renaming declarations.
-- Enter new name and indicate that it renames the generic unit.
procedure Analyze_Renamed_Character
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Renamed entity is given by a character literal, which must belong
-- to the return type of the new entity. Is_Body indicates whether the
-- declaration is a renaming_as_body. If the original declaration has
-- already been frozen (because of an intervening body, e.g.) the body of
-- the function must be built now. The same applies to the following
-- various renaming procedures.
procedure Analyze_Renamed_Dereference
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Renamed entity is given by an explicit dereference. Prefix must be a
-- conformant access_to_subprogram type.
procedure Analyze_Renamed_Entry
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- If the renamed entity in a subprogram renaming is an entry or protected
-- subprogram, build a body for the new entity whose only statement is a
-- call to the renamed entity.
procedure Analyze_Renamed_Family_Member
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- Used when the renamed entity is an indexed component. The prefix must
-- denote an entry family.
procedure Analyze_Renamed_Primitive_Operation
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean);
-- If the renamed entity in a subprogram renaming is a primitive operation
-- or a class-wide operation in prefix form, save the target object,
-- which must be added to the list of actuals in any subsequent call.
-- The renaming operation is intrinsic because the compiler must in
-- fact generate a wrapper for it (6.3.1 (10 1/2)).
function Applicable_Use (Pack_Name : Node_Id) return Boolean;
-- Common code to Use_One_Package and Set_Use, to determine whether use
-- clause must be processed. Pack_Name is an entity name that references
-- the package in question.
procedure Attribute_Renaming (N : Node_Id);
-- Analyze renaming of attribute as subprogram. The renaming declaration N
-- is rewritten as a subprogram body that returns the attribute reference
-- applied to the formals of the function.
procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id);
-- Set Entity, with style check if need be. For a discriminant reference,
-- replace by the corresponding discriminal, i.e. the parameter of the
-- initialization procedure that corresponds to the discriminant.
procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id);
-- A renaming_as_body may occur after the entity of the original decla-
-- ration has been frozen. In that case, the body of the new entity must
-- be built now, because the usual mechanism of building the renamed
-- body at the point of freezing will not work. Subp is the subprogram
-- for which N provides the Renaming_As_Body.
procedure Check_In_Previous_With_Clause
(N : Node_Id;
Nam : Node_Id);
-- N is a use_package clause and Nam the package name, or N is a use_type
-- clause and Nam is the prefix of the type name. In either case, verify
-- that the package is visible at that point in the context: either it
-- appears in a previous with_clause, or because it is a fully qualified
-- name and the root ancestor appears in a previous with_clause.
procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id);
-- Verify that the entity in a renaming declaration that is a library unit
-- is itself a library unit and not a nested unit or subunit. Also check
-- that if the renaming is a child unit of a generic parent, then the
-- renamed unit must also be a child unit of that parent. Finally, verify
-- that a renamed generic unit is not an implicit child declared within
-- an instance of the parent.
procedure Chain_Use_Clause (N : Node_Id);
-- Chain use clause onto list of uses clauses headed by First_Use_Clause in
-- the proper scope table entry. This is usually the current scope, but it
-- will be an inner scope when installing the use clauses of the private
-- declarations of a parent unit prior to compiling the private part of a
-- child unit. This chain is traversed when installing/removing use clauses
-- when compiling a subunit or instantiating a generic body on the fly,
-- when it is necessary to save and restore full environments.
function Enclosing_Instance return Entity_Id;
-- In an instance nested within another one, several semantic checks are
-- unnecessary because the legality of the nested instance has been checked
-- in the enclosing generic unit. This applies in particular to legality
-- checks on actuals for formal subprograms of the inner instance, which
-- are checked as subprogram renamings, and may be complicated by confusion
-- in private/full views. This function returns the instance enclosing the
-- current one if there is such, else it returns Empty.
--
-- If the renaming determines the entity for the default of a formal
-- subprogram nested within another instance, choose the innermost
-- candidate. This is because if the formal has a box, and we are within
-- an enclosing instance where some candidate interpretations are local
-- to this enclosing instance, we know that the default was properly
-- resolved when analyzing the generic, so we prefer the local
-- candidates to those that are external. This is not always the case
-- but is a reasonable heuristic on the use of nested generics. The
-- proper solution requires a full renaming model.
function Has_Implicit_Character_Literal (N : Node_Id) return Boolean;
-- Find a type derived from Character or Wide_Character in the prefix of N.
-- Used to resolved qualified names whose selector is a character literal.
function Has_Private_With (E : Entity_Id) return Boolean;
-- Ada 2005 (AI-262): Determines if the current compilation unit has a
-- private with on E.
procedure Find_Expanded_Name (N : Node_Id);
-- The input is a selected component known to be an expanded name. Verify
-- legality of selector given the scope denoted by prefix, and change node
-- N into a expanded name with a properly set Entity field.
function Find_Renamed_Entity
(N : Node_Id;
Nam : Node_Id;
New_S : Entity_Id;
Is_Actual : Boolean := False) return Entity_Id;
-- Find the renamed entity that corresponds to the given parameter profile
-- in a subprogram renaming declaration. The renamed entity may be an
-- operator, a subprogram, an entry, or a protected operation. Is_Actual
-- indicates that the renaming is the one generated for an actual subpro-
-- gram in an instance, for which special visibility checks apply.
function Has_Implicit_Operator (N : Node_Id) return Boolean;
-- N is an expanded name whose selector is an operator name (e.g. P."+").
-- declarative part contains an implicit declaration of an operator if it
-- has a declaration of a type to which one of the predefined operators
-- apply. The existence of this routine is an implementation artifact. A
-- more straightforward but more space-consuming choice would be to make
-- all inherited operators explicit in the symbol table.
procedure Inherit_Renamed_Profile (New_S : Entity_Id; Old_S : Entity_Id);
-- A subprogram defined by a renaming declaration inherits the parameter
-- profile of the renamed entity. The subtypes given in the subprogram
-- specification are discarded and replaced with those of the renamed
-- subprogram, which are then used to recheck the default values.
function Is_Appropriate_For_Record (T : Entity_Id) return Boolean;
-- Prefix is appropriate for record if it is of a record type, or an access
-- to such.
function Is_Appropriate_For_Entry_Prefix (T : Entity_Id) return Boolean;
-- True if it is of a task type, a protected type, or else an access to one
-- of these types.
procedure Note_Redundant_Use (Clause : Node_Id);
-- Mark the name in a use clause as redundant if the corresponding entity
-- is already use-visible. Emit a warning if the use clause comes from
-- source and the proper warnings are enabled.
procedure Premature_Usage (N : Node_Id);
-- Diagnose usage of an entity before it is visible
procedure Use_One_Package (P : Entity_Id; N : Node_Id);
-- Make visible entities declared in package P potentially use-visible
-- in the current context. Also used in the analysis of subunits, when
-- re-installing use clauses of parent units. N is the use_clause that
-- names P (and possibly other packages).
procedure Use_One_Type (Id : Node_Id; Installed : Boolean := False);
-- Id is the subtype mark from a use type clause. This procedure makes
-- the primitive operators of the type potentially use-visible. The
-- boolean flag Installed indicates that the clause is being reinstalled
-- after previous analysis, and primitive operations are already chained
-- on the Used_Operations list of the clause.
procedure Write_Info;
-- Write debugging information on entities declared in current scope
--------------------------------
-- Analyze_Exception_Renaming --
--------------------------------
-- The language only allows a single identifier, but the tree holds an
-- identifier list. The parser has already issued an error message if
-- there is more than one element in the list.
procedure Analyze_Exception_Renaming (N : Node_Id) is
Id : constant Node_Id := Defining_Identifier (N);
Nam : constant Node_Id := Name (N);
begin
-- The exception renaming declaration may be subject to pragma Ghost
-- with policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged as
-- ignored Ghost.
Set_Ghost_Mode (N);
Check_SPARK_05_Restriction ("exception renaming is not allowed", N);
Enter_Name (Id);
Analyze (Nam);
Set_Ekind (Id, E_Exception);
Set_Etype (Id, Standard_Exception_Type);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
if not Is_Entity_Name (Nam)
or else Ekind (Entity (Nam)) /= E_Exception
then
Error_Msg_N ("invalid exception name in renaming", Nam);
else
if Present (Renamed_Object (Entity (Nam))) then
Set_Renamed_Object (Id, Renamed_Object (Entity (Nam)));
else
Set_Renamed_Object (Id, Entity (Nam));
end if;
-- An exception renaming is Ghost if the renamed entity is Ghost or
-- the construct appears within a Ghost scope.
if Is_Ghost_Entity (Entity (Nam)) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (Id);
end if;
end if;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
end Analyze_Exception_Renaming;
---------------------------
-- Analyze_Expanded_Name --
---------------------------
procedure Analyze_Expanded_Name (N : Node_Id) is
begin
-- If the entity pointer is already set, this is an internal node, or a
-- node that is analyzed more than once, after a tree modification. In
-- such a case there is no resolution to perform, just set the type. For
-- completeness, analyze prefix as well.
if Present (Entity (N)) then
if Is_Type (Entity (N)) then
Set_Etype (N, Entity (N));
else
Set_Etype (N, Etype (Entity (N)));
end if;
Analyze (Prefix (N));
return;
else
Find_Expanded_Name (N);
end if;
Analyze_Dimension (N);
end Analyze_Expanded_Name;
---------------------------------------
-- Analyze_Generic_Function_Renaming --
---------------------------------------
procedure Analyze_Generic_Function_Renaming (N : Node_Id) is
begin
Analyze_Generic_Renaming (N, E_Generic_Function);
end Analyze_Generic_Function_Renaming;
--------------------------------------
-- Analyze_Generic_Package_Renaming --
--------------------------------------
procedure Analyze_Generic_Package_Renaming (N : Node_Id) is
begin
-- Test for the Text_IO special unit case here, since we may be renaming
-- one of the subpackages of Text_IO, then join common routine.
Check_Text_IO_Special_Unit (Name (N));
Analyze_Generic_Renaming (N, E_Generic_Package);
end Analyze_Generic_Package_Renaming;
----------------------------------------
-- Analyze_Generic_Procedure_Renaming --
----------------------------------------
procedure Analyze_Generic_Procedure_Renaming (N : Node_Id) is
begin
Analyze_Generic_Renaming (N, E_Generic_Procedure);
end Analyze_Generic_Procedure_Renaming;
------------------------------
-- Analyze_Generic_Renaming --
------------------------------
procedure Analyze_Generic_Renaming
(N : Node_Id;
K : Entity_Kind)
is
New_P : constant Entity_Id := Defining_Entity (N);
Old_P : Entity_Id;
Inst : Boolean := False; -- prevent junk warning
begin
if Name (N) = Error then
return;
end if;
-- The generic renaming declaration may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
Check_SPARK_05_Restriction ("generic renaming is not allowed", N);
Generate_Definition (New_P);
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_P, Is_Pure (Current_Scope));
end if;
if Nkind (Name (N)) = N_Selected_Component then
Check_Generic_Child_Unit (Name (N), Inst);
else
Analyze (Name (N));
end if;
if not Is_Entity_Name (Name (N)) then
Error_Msg_N ("expect entity name in renaming declaration", Name (N));
Old_P := Any_Id;
else
Old_P := Entity (Name (N));
end if;
Enter_Name (New_P);
Set_Ekind (New_P, K);
if Etype (Old_P) = Any_Type then
null;
elsif Ekind (Old_P) /= K then
Error_Msg_N ("invalid generic unit name", Name (N));
else
if Present (Renamed_Object (Old_P)) then
Set_Renamed_Object (New_P, Renamed_Object (Old_P));
else
Set_Renamed_Object (New_P, Old_P);
end if;
Set_Is_Pure (New_P, Is_Pure (Old_P));
Set_Is_Preelaborated (New_P, Is_Preelaborated (Old_P));
Set_Etype (New_P, Etype (Old_P));
Set_Has_Completion (New_P);
-- An generic renaming is Ghost if the renamed entity is Ghost or the
-- construct appears within a Ghost scope.
if Is_Ghost_Entity (Old_P) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (New_P);
end if;
if In_Open_Scopes (Old_P) then
Error_Msg_N ("within its scope, generic denotes its instance", N);
end if;
-- For subprograms, propagate the Intrinsic flag, to allow, e.g.
-- renamings and subsequent instantiations of Unchecked_Conversion.
if Ekind_In (Old_P, E_Generic_Function, E_Generic_Procedure) then
Set_Is_Intrinsic_Subprogram
(New_P, Is_Intrinsic_Subprogram (Old_P));
end if;
Check_Library_Unit_Renaming (N, Old_P);
end if;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_P);
end if;
end Analyze_Generic_Renaming;
-----------------------------
-- Analyze_Object_Renaming --
-----------------------------
procedure Analyze_Object_Renaming (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Id : constant Entity_Id := Defining_Identifier (N);
Dec : Node_Id;
Nam : constant Node_Id := Name (N);
T : Entity_Id;
T2 : Entity_Id;
procedure Check_Constrained_Object;
-- If the nominal type is unconstrained but the renamed object is
-- constrained, as can happen with renaming an explicit dereference or
-- a function return, build a constrained subtype from the object. If
-- the renaming is for a formal in an accept statement, the analysis
-- has already established its actual subtype. This is only relevant
-- if the renamed object is an explicit dereference.
function In_Generic_Scope (E : Entity_Id) return Boolean;
-- Determine whether entity E is inside a generic cope
------------------------------
-- Check_Constrained_Object --
------------------------------
procedure Check_Constrained_Object is
Typ : constant Entity_Id := Etype (Nam);
Subt : Entity_Id;
begin
if Nkind_In (Nam, N_Function_Call, N_Explicit_Dereference)
and then Is_Composite_Type (Etype (Nam))
and then not Is_Constrained (Etype (Nam))
and then not Has_Unknown_Discriminants (Etype (Nam))
and then Expander_Active
then
-- If Actual_Subtype is already set, nothing to do
if Ekind_In (Id, E_Variable, E_Constant)
and then Present (Actual_Subtype (Id))
then
null;
-- A renaming of an unchecked union has no actual subtype
elsif Is_Unchecked_Union (Typ) then
null;
-- If a record is limited its size is invariant. This is the case
-- in particular with record types with an access discirminant
-- that are used in iterators. This is an optimization, but it
-- also prevents typing anomalies when the prefix is further
-- expanded. Limited types with discriminants are included.
elsif Is_Limited_Record (Typ)
or else
(Ekind (Typ) = E_Limited_Private_Type
and then Has_Discriminants (Typ)
and then Is_Access_Type (Etype (First_Discriminant (Typ))))
then
null;
else
Subt := Make_Temporary (Loc, 'T');
Remove_Side_Effects (Nam);
Insert_Action (N,
Make_Subtype_Declaration (Loc,
Defining_Identifier => Subt,
Subtype_Indication =>
Make_Subtype_From_Expr (Nam, Typ)));
Rewrite (Subtype_Mark (N), New_Occurrence_Of (Subt, Loc));
Set_Etype (Nam, Subt);
-- Freeze subtype at once, to prevent order of elaboration
-- issues in the backend. The renamed object exists, so its
-- type is already frozen in any case.
Freeze_Before (N, Subt);
end if;
end if;
end Check_Constrained_Object;
----------------------
-- In_Generic_Scope --
----------------------
function In_Generic_Scope (E : Entity_Id) return Boolean is
S : Entity_Id;
begin
S := Scope (E);
while Present (S) and then S /= Standard_Standard loop
if Is_Generic_Unit (S) then
return True;
end if;
S := Scope (S);
end loop;
return False;
end In_Generic_Scope;
-- Start of processing for Analyze_Object_Renaming
begin
if Nam = Error then
return;
end if;
-- The object renaming declaration may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
Check_SPARK_05_Restriction ("object renaming is not allowed", N);
Set_Is_Pure (Id, Is_Pure (Current_Scope));
Enter_Name (Id);
-- The renaming of a component that depends on a discriminant requires
-- an actual subtype, because in subsequent use of the object Gigi will
-- be unable to locate the actual bounds. This explicit step is required
-- when the renaming is generated in removing side effects of an
-- already-analyzed expression.
if Nkind (Nam) = N_Selected_Component and then Analyzed (Nam) then
T := Etype (Nam);
Dec := Build_Actual_Subtype_Of_Component (Etype (Nam), Nam);
if Present (Dec) then
Insert_Action (N, Dec);
T := Defining_Identifier (Dec);
Set_Etype (Nam, T);
end if;
-- Complete analysis of the subtype mark in any case, for ASIS use
if Present (Subtype_Mark (N)) then
Find_Type (Subtype_Mark (N));
end if;
elsif Present (Subtype_Mark (N)) then
Find_Type (Subtype_Mark (N));
T := Entity (Subtype_Mark (N));
Analyze (Nam);
-- Reject renamings of conversions unless the type is tagged, or
-- the conversion is implicit (which can occur for cases of anonymous
-- access types in Ada 2012).
if Nkind (Nam) = N_Type_Conversion
and then Comes_From_Source (Nam)
and then not Is_Tagged_Type (T)
then
Error_Msg_N
("renaming of conversion only allowed for tagged types", Nam);
end if;
Resolve (Nam, T);
-- If the renamed object is a function call of a limited type,
-- the expansion of the renaming is complicated by the presence
-- of various temporaries and subtypes that capture constraints
-- of the renamed object. Rewrite node as an object declaration,
-- whose expansion is simpler. Given that the object is limited
-- there is no copy involved and no performance hit.
if Nkind (Nam) = N_Function_Call
and then Is_Limited_View (Etype (Nam))
and then not Is_Constrained (Etype (Nam))
and then Comes_From_Source (N)
then
Set_Etype (Id, T);
Set_Ekind (Id, E_Constant);
Rewrite (N,
Make_Object_Declaration (Loc,
Defining_Identifier => Id,
Constant_Present => True,
Object_Definition => New_Occurrence_Of (Etype (Nam), Loc),
Expression => Relocate_Node (Nam)));
return;
end if;
-- Ada 2012 (AI05-149): Reject renaming of an anonymous access object
-- when renaming declaration has a named access type. The Ada 2012
-- coverage rules allow an anonymous access type in the context of
-- an expected named general access type, but the renaming rules
-- require the types to be the same. (An exception is when the type
-- of the renaming is also an anonymous access type, which can only
-- happen due to a renaming created by the expander.)
if Nkind (Nam) = N_Type_Conversion
and then not Comes_From_Source (Nam)
and then Ekind (Etype (Expression (Nam))) = E_Anonymous_Access_Type
and then Ekind (T) /= E_Anonymous_Access_Type
then
Wrong_Type (Expression (Nam), T); -- Should we give better error???
end if;
-- Check that a class-wide object is not being renamed as an object
-- of a specific type. The test for access types is needed to exclude
-- cases where the renamed object is a dynamically tagged access
-- result, such as occurs in certain expansions.
if Is_Tagged_Type (T) then
Check_Dynamically_Tagged_Expression
(Expr => Nam,
Typ => T,
Related_Nod => N);
end if;
-- Ada 2005 (AI-230/AI-254): Access renaming
else pragma Assert (Present (Access_Definition (N)));
T := Access_Definition
(Related_Nod => N,
N => Access_Definition (N));
Analyze (Nam);
-- Ada 2005 AI05-105: if the declaration has an anonymous access
-- type, the renamed object must also have an anonymous type, and
-- this is a name resolution rule. This was implicit in the last part
-- of the first sentence in 8.5.1(3/2), and is made explicit by this
-- recent AI.
if not Is_Overloaded (Nam) then
if Ekind (Etype (Nam)) /= Ekind (T) then
Error_Msg_N
("expect anonymous access type in object renaming", N);
end if;
else
declare
I : Interp_Index;
It : Interp;
Typ : Entity_Id := Empty;
Seen : Boolean := False;
begin
Get_First_Interp (Nam, I, It);
while Present (It.Typ) loop
-- Renaming is ambiguous if more than one candidate
-- interpretation is type-conformant with the context.
if Ekind (It.Typ) = Ekind (T) then
if Ekind (T) = E_Anonymous_Access_Subprogram_Type
and then
Type_Conformant
(Designated_Type (T), Designated_Type (It.Typ))
then
if not Seen then
Seen := True;
else
Error_Msg_N
("ambiguous expression in renaming", Nam);
end if;
elsif Ekind (T) = E_Anonymous_Access_Type
and then
Covers (Designated_Type (T), Designated_Type (It.Typ))
then
if not Seen then
Seen := True;
else
Error_Msg_N
("ambiguous expression in renaming", Nam);
end if;
end if;
if Covers (T, It.Typ) then
Typ := It.Typ;
Set_Etype (Nam, Typ);
Set_Is_Overloaded (Nam, False);
end if;
end if;
Get_Next_Interp (I, It);
end loop;
end;
end if;
Resolve (Nam, T);
-- Ada 2005 (AI-231): In the case where the type is defined by an
-- access_definition, the renamed entity shall be of an access-to-
-- constant type if and only if the access_definition defines an
-- access-to-constant type. ARM 8.5.1(4)
if Constant_Present (Access_Definition (N))
and then not Is_Access_Constant (Etype (Nam))
then
Error_Msg_N ("(Ada 2005): the renamed object is not "
& "access-to-constant (RM 8.5.1(6))", N);
elsif not Constant_Present (Access_Definition (N))
and then Is_Access_Constant (Etype (Nam))
then
Error_Msg_N ("(Ada 2005): the renamed object is not "
& "access-to-variable (RM 8.5.1(6))", N);
end if;
if Is_Access_Subprogram_Type (Etype (Nam)) then
Check_Subtype_Conformant
(Designated_Type (T), Designated_Type (Etype (Nam)));
elsif not Subtypes_Statically_Match
(Designated_Type (T),
Available_View (Designated_Type (Etype (Nam))))
then
Error_Msg_N
("subtype of renamed object does not statically match", N);
end if;
end if;
-- Special processing for renaming function return object. Some errors
-- and warnings are produced only for calls that come from source.
if Nkind (Nam) = N_Function_Call then
case Ada_Version is
-- Usage is illegal in Ada 83, but renamings are also introduced
-- during expansion, and error does not apply to those.
when Ada_83 =>
if Comes_From_Source (N) then
Error_Msg_N
("(Ada 83) cannot rename function return object", Nam);
end if;
-- In Ada 95, warn for odd case of renaming parameterless function
-- call if this is not a limited type (where this is useful).
when others =>
if Warn_On_Object_Renames_Function
and then No (Parameter_Associations (Nam))
and then not Is_Limited_Type (Etype (Nam))
and then Comes_From_Source (Nam)
then
Error_Msg_N
("renaming function result object is suspicious?R?", Nam);
Error_Msg_NE
("\function & will be called only once?R?", Nam,
Entity (Name (Nam)));
Error_Msg_N -- CODEFIX
("\suggest using an initialized constant "
& "object instead?R?", Nam);
end if;
end case;
end if;
Check_Constrained_Object;
-- An object renaming requires an exact match of the type. Class-wide
-- matching is not allowed.
if Is_Class_Wide_Type (T)
and then Base_Type (Etype (Nam)) /= Base_Type (T)
then
Wrong_Type (Nam, T);
end if;
T2 := Etype (Nam);
-- Ada 2005 (AI-326): Handle wrong use of incomplete type
if Nkind (Nam) = N_Explicit_Dereference
and then Ekind (Etype (T2)) = E_Incomplete_Type
then
Error_Msg_NE ("invalid use of incomplete type&", Id, T2);
return;
elsif Ekind (Etype (T)) = E_Incomplete_Type then
Error_Msg_NE ("invalid use of incomplete type&", Id, T);
return;
end if;
-- Ada 2005 (AI-327)
if Ada_Version >= Ada_2005
and then Nkind (Nam) = N_Attribute_Reference
and then Attribute_Name (Nam) = Name_Priority
then
null;
elsif Ada_Version >= Ada_2005 and then Nkind (Nam) in N_Has_Entity then
declare
Nam_Decl : Node_Id;
Nam_Ent : Entity_Id;
begin
if Nkind (Nam) = N_Attribute_Reference then
Nam_Ent := Entity (Prefix (Nam));
else
Nam_Ent := Entity (Nam);
end if;
Nam_Decl := Parent (Nam_Ent);
if Has_Null_Exclusion (N)
and then not Has_Null_Exclusion (Nam_Decl)
then
-- Ada 2005 (AI-423): If the object name denotes a generic
-- formal object of a generic unit G, and the object renaming
-- declaration occurs within the body of G or within the body
-- of a generic unit declared within the declarative region
-- of G, then the declaration of the formal object of G must
-- have a null exclusion or a null-excluding subtype.
if Is_Formal_Object (Nam_Ent)
and then In_Generic_Scope (Id)
then
if not Can_Never_Be_Null (Etype (Nam_Ent)) then
Error_Msg_N
("renamed formal does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
elsif In_Package_Body (Scope (Id)) then
Error_Msg_N
("formal object does not have a null exclusion"
& "(RM 8.5.1(4.6/2))", N);
end if;
-- Ada 2005 (AI-423): Otherwise, the subtype of the object name
-- shall exclude null.
elsif not Can_Never_Be_Null (Etype (Nam_Ent)) then
Error_Msg_N
("renamed object does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
-- An instance is illegal if it contains a renaming that
-- excludes null, and the actual does not. The renaming
-- declaration has already indicated that the declaration
-- of the renamed actual in the instance will raise
-- constraint_error.
elsif Nkind (Nam_Decl) = N_Object_Declaration
and then In_Instance
and then
Present (Corresponding_Generic_Association (Nam_Decl))
and then Nkind (Expression (Nam_Decl)) =
N_Raise_Constraint_Error
then
Error_Msg_N
("renamed actual does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
-- Finally, if there is a null exclusion, the subtype mark
-- must not be null-excluding.
elsif No (Access_Definition (N))
and then Can_Never_Be_Null (T)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)",
N, T);
end if;
elsif Can_Never_Be_Null (T)
and then not Can_Never_Be_Null (Etype (Nam_Ent))
then
Error_Msg_N
("renamed object does not exclude `NULL` "
& "(RM 8.5.1(4.6/2))", N);
elsif Has_Null_Exclusion (N)
and then No (Access_Definition (N))
and then Can_Never_Be_Null (T)
then
Error_Msg_NE
("`NOT NULL` not allowed (& already excludes null)", N, T);
end if;
end;
end if;
-- Set the Ekind of the entity, unless it has been set already, as is
-- the case for the iteration object over a container with no variable
-- indexing. In that case it's been marked as a constant, and we do not
-- want to change it to a variable.
if Ekind (Id) /= E_Constant then
Set_Ekind (Id, E_Variable);
end if;
-- Initialize the object size and alignment. Note that we used to call
-- Init_Size_Align here, but that's wrong for objects which have only
-- an Esize, not an RM_Size field.
Init_Object_Size_Align (Id);
if T = Any_Type or else Etype (Nam) = Any_Type then
return;
-- Verify that the renamed entity is an object or a function call. It
-- may have been rewritten in several ways.
elsif Is_Object_Reference (Nam) then
if Comes_From_Source (N) then
if Is_Dependent_Component_Of_Mutable_Object (Nam) then
Error_Msg_N
("illegal renaming of discriminant-dependent component", Nam);
end if;
-- If the renaming comes from source and the renamed object is a
-- dereference, then mark the prefix as needing debug information,
-- since it might have been rewritten hence internally generated
-- and Debug_Renaming_Declaration will link the renaming to it.
if Nkind (Nam) = N_Explicit_Dereference
and then Is_Entity_Name (Prefix (Nam))
then
Set_Debug_Info_Needed (Entity (Prefix (Nam)));
end if;
end if;
-- A static function call may have been folded into a literal
elsif Nkind (Original_Node (Nam)) = N_Function_Call
-- When expansion is disabled, attribute reference is not rewritten
-- as function call. Otherwise it may be rewritten as a conversion,
-- so check original node.
or else (Nkind (Original_Node (Nam)) = N_Attribute_Reference
and then Is_Function_Attribute_Name
(Attribute_Name (Original_Node (Nam))))
-- Weird but legal, equivalent to renaming a function call. Illegal
-- if the literal is the result of constant-folding an attribute
-- reference that is not a function.
or else (Is_Entity_Name (Nam)
and then Ekind (Entity (Nam)) = E_Enumeration_Literal
and then
Nkind (Original_Node (Nam)) /= N_Attribute_Reference)
or else (Nkind (Nam) = N_Type_Conversion
and then Is_Tagged_Type (Entity (Subtype_Mark (Nam))))
then
null;
elsif Nkind (Nam) = N_Type_Conversion then
Error_Msg_N
("renaming of conversion only allowed for tagged types", Nam);
-- Ada 2005 (AI-327)
elsif Ada_Version >= Ada_2005
and then Nkind (Nam) = N_Attribute_Reference
and then Attribute_Name (Nam) = Name_Priority
then
null;
-- Allow internally generated x'Reference expression
elsif Nkind (Nam) = N_Reference then
null;
else
Error_Msg_N ("expect object name in renaming", Nam);
end if;
Set_Etype (Id, T2);
if not Is_Variable (Nam) then
Set_Ekind (Id, E_Constant);
Set_Never_Set_In_Source (Id, True);
Set_Is_True_Constant (Id, True);
end if;
-- An object renaming is Ghost if the renamed entity is Ghost or the
-- construct appears within a Ghost scope.
if (Is_Entity_Name (Nam)
and then Is_Ghost_Entity (Entity (Nam)))
or else Ghost_Mode > None
then
Set_Is_Ghost_Entity (Id);
end if;
-- The entity of the renaming declaration needs to reflect whether the
-- renamed object is volatile. Is_Volatile is set if the renamed object
-- is volatile in the RM legality sense.
Set_Is_Volatile (Id, Is_Volatile_Object (Nam));
-- Treat as volatile if we just set the Volatile flag
if Is_Volatile (Id)
-- Or if we are renaming an entity which was marked this way
-- Are there more cases, e.g. X(J) where X is Treat_As_Volatile ???
or else (Is_Entity_Name (Nam)
and then Treat_As_Volatile (Entity (Nam)))
then
Set_Treat_As_Volatile (Id, True);
end if;
-- Now make the link to the renamed object
Set_Renamed_Object (Id, Nam);
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, Id);
end if;
-- Deal with dimensions
Analyze_Dimension (N);
end Analyze_Object_Renaming;
------------------------------
-- Analyze_Package_Renaming --
------------------------------
procedure Analyze_Package_Renaming (N : Node_Id) is
New_P : constant Entity_Id := Defining_Entity (N);
Old_P : Entity_Id;
Spec : Node_Id;
begin
if Name (N) = Error then
return;
end if;
-- The package renaming declaration may be subject to pragma Ghost with
-- policy Ignore. Set the mode now to ensure that any nodes generated
-- during analysis and expansion are properly flagged as ignored Ghost.
Set_Ghost_Mode (N);
-- Check for Text_IO special unit (we may be renaming a Text_IO child)
Check_Text_IO_Special_Unit (Name (N));
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_P, Is_Pure (Current_Scope));
end if;
Enter_Name (New_P);
Analyze (Name (N));
if Is_Entity_Name (Name (N)) then
Old_P := Entity (Name (N));
else
Old_P := Any_Id;
end if;
if Etype (Old_P) = Any_Type then
Error_Msg_N ("expect package name in renaming", Name (N));
elsif Ekind (Old_P) /= E_Package
and then not (Ekind (Old_P) = E_Generic_Package
and then In_Open_Scopes (Old_P))
then
if Ekind (Old_P) = E_Generic_Package then
Error_Msg_N
("generic package cannot be renamed as a package", Name (N));
else
Error_Msg_Sloc := Sloc (Old_P);
Error_Msg_NE
("expect package name in renaming, found& declared#",
Name (N), Old_P);
end if;
-- Set basic attributes to minimize cascaded errors
Set_Ekind (New_P, E_Package);
Set_Etype (New_P, Standard_Void_Type);
-- Here for OK package renaming
else
-- Entities in the old package are accessible through the renaming
-- entity. The simplest implementation is to have both packages share
-- the entity list.
Set_Ekind (New_P, E_Package);
Set_Etype (New_P, Standard_Void_Type);
if Present (Renamed_Object (Old_P)) then
Set_Renamed_Object (New_P, Renamed_Object (Old_P));
else
Set_Renamed_Object (New_P, Old_P);
end if;
Set_Has_Completion (New_P);
Set_First_Entity (New_P, First_Entity (Old_P));
Set_Last_Entity (New_P, Last_Entity (Old_P));
Set_First_Private_Entity (New_P, First_Private_Entity (Old_P));
Check_Library_Unit_Renaming (N, Old_P);
Generate_Reference (Old_P, Name (N));
-- A package renaming is Ghost if the renamed entity is Ghost or
-- the construct appears within a Ghost scope.
if Is_Ghost_Entity (Old_P) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (New_P);
end if;
-- If the renaming is in the visible part of a package, then we set
-- Renamed_In_Spec for the renamed package, to prevent giving
-- warnings about no entities referenced. Such a warning would be
-- overenthusiastic, since clients can see entities in the renamed
-- package via the visible package renaming.
declare
Ent : constant Entity_Id := Cunit_Entity (Current_Sem_Unit);
begin
if Ekind (Ent) = E_Package
and then not In_Private_Part (Ent)
and then In_Extended_Main_Source_Unit (N)
and then Ekind (Old_P) = E_Package
then
Set_Renamed_In_Spec (Old_P);
end if;
end;
-- If this is the renaming declaration of a package instantiation
-- within itself, it is the declaration that ends the list of actuals
-- for the instantiation. At this point, the subtypes that rename
-- the actuals are flagged as generic, to avoid spurious ambiguities
-- if the actuals for two distinct formals happen to coincide. If
-- the actual is a private type, the subtype has a private completion
-- that is flagged in the same fashion.
-- Resolution is identical to what is was in the original generic.
-- On exit from the generic instance, these are turned into regular
-- subtypes again, so they are compatible with types in their class.
if not Is_Generic_Instance (Old_P) then
return;
else
Spec := Specification (Unit_Declaration_Node (Old_P));
end if;
if Nkind (Spec) = N_Package_Specification
and then Present (Generic_Parent (Spec))
and then Old_P = Current_Scope
and then Chars (New_P) = Chars (Generic_Parent (Spec))
then
declare
E : Entity_Id;
begin
E := First_Entity (Old_P);
while Present (E) and then E /= New_P loop
if Is_Type (E)
and then Nkind (Parent (E)) = N_Subtype_Declaration
then
Set_Is_Generic_Actual_Type (E);
if Is_Private_Type (E)
and then Present (Full_View (E))
then
Set_Is_Generic_Actual_Type (Full_View (E));
end if;
end if;
Next_Entity (E);
end loop;
end;
end if;
end if;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_P);
end if;
end Analyze_Package_Renaming;
-------------------------------
-- Analyze_Renamed_Character --
-------------------------------
procedure Analyze_Renamed_Character
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
C : constant Node_Id := Name (N);
begin
if Ekind (New_S) = E_Function then
Resolve (C, Etype (New_S));
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
else
Error_Msg_N ("character literal can only be renamed as function", N);
end if;
end Analyze_Renamed_Character;
---------------------------------
-- Analyze_Renamed_Dereference --
---------------------------------
procedure Analyze_Renamed_Dereference
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : constant Node_Id := Name (N);
P : constant Node_Id := Prefix (Nam);
Typ : Entity_Id;
Ind : Interp_Index;
It : Interp;
begin
if not Is_Overloaded (P) then
if Ekind (Etype (Nam)) /= E_Subprogram_Type
or else not Type_Conformant (Etype (Nam), New_S)
then
Error_Msg_N ("designated type does not match specification", P);
else
Resolve (P);
end if;
return;
else
Typ := Any_Type;
Get_First_Interp (Nam, Ind, It);
while Present (It.Nam) loop
if Ekind (It.Nam) = E_Subprogram_Type
and then Type_Conformant (It.Nam, New_S)
then
if Typ /= Any_Id then
Error_Msg_N ("ambiguous renaming", P);
return;
else
Typ := It.Nam;
end if;
end if;
Get_Next_Interp (Ind, It);
end loop;
if Typ = Any_Type then
Error_Msg_N ("designated type does not match specification", P);
else
Resolve (N, Typ);
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end if;
end if;
end Analyze_Renamed_Dereference;
---------------------------
-- Analyze_Renamed_Entry --
---------------------------
procedure Analyze_Renamed_Entry
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : constant Node_Id := Name (N);
Sel : constant Node_Id := Selector_Name (Nam);
Is_Actual : constant Boolean := Present (Corresponding_Formal_Spec (N));
Old_S : Entity_Id;
begin
if Entity (Sel) = Any_Id then
-- Selector is undefined on prefix. Error emitted already
Set_Has_Completion (New_S);
return;
end if;
-- Otherwise find renamed entity and build body of New_S as a call to it
Old_S := Find_Renamed_Entity (N, Selector_Name (Nam), New_S);
if Old_S = Any_Id then
Error_Msg_N (" no subprogram or entry matches specification", N);
else
if Is_Body then
Check_Subtype_Conformant (New_S, Old_S, N);
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
else
-- Only mode conformance required for a renaming_as_declaration
Check_Mode_Conformant (New_S, Old_S, N);
end if;
Inherit_Renamed_Profile (New_S, Old_S);
-- The prefix can be an arbitrary expression that yields a task or
-- protected object, so it must be resolved.
Resolve (Prefix (Nam), Scope (Old_S));
end if;
Set_Convention (New_S, Convention (Old_S));
Set_Has_Completion (New_S, Inside_A_Generic);
-- AI05-0225: If the renamed entity is a procedure or entry of a
-- protected object, the target object must be a variable.
if Ekind (Scope (Old_S)) in Protected_Kind
and then Ekind (New_S) = E_Procedure
and then not Is_Variable (Prefix (Nam))
then
if Is_Actual then
Error_Msg_N
("target object of protected operation used as actual for "
& "formal procedure must be a variable", Nam);
else
Error_Msg_N
("target object of protected operation renamed as procedure, "
& "must be a variable", Nam);
end if;
end if;
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end Analyze_Renamed_Entry;
-----------------------------------
-- Analyze_Renamed_Family_Member --
-----------------------------------
procedure Analyze_Renamed_Family_Member
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Nam : constant Node_Id := Name (N);
P : constant Node_Id := Prefix (Nam);
Old_S : Entity_Id;
begin
if (Is_Entity_Name (P) and then Ekind (Entity (P)) = E_Entry_Family)
or else (Nkind (P) = N_Selected_Component
and then Ekind (Entity (Selector_Name (P))) = E_Entry_Family)
then
if Is_Entity_Name (P) then
Old_S := Entity (P);
else
Old_S := Entity (Selector_Name (P));
end if;
if not Entity_Matches_Spec (Old_S, New_S) then
Error_Msg_N ("entry family does not match specification", N);
elsif Is_Body then
Check_Subtype_Conformant (New_S, Old_S, N);
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
end if;
else
Error_Msg_N ("no entry family matches specification", N);
end if;
Set_Has_Completion (New_S, Inside_A_Generic);
if Is_Body then
Check_Frozen_Renaming (N, New_S);
end if;
end Analyze_Renamed_Family_Member;
-----------------------------------------
-- Analyze_Renamed_Primitive_Operation --
-----------------------------------------
procedure Analyze_Renamed_Primitive_Operation
(N : Node_Id;
New_S : Entity_Id;
Is_Body : Boolean)
is
Old_S : Entity_Id;
function Conforms
(Subp : Entity_Id;
Ctyp : Conformance_Type) return Boolean;
-- Verify that the signatures of the renamed entity and the new entity
-- match. The first formal of the renamed entity is skipped because it
-- is the target object in any subsequent call.
--------------
-- Conforms --
--------------
function Conforms
(Subp : Entity_Id;
Ctyp : Conformance_Type) return Boolean
is
Old_F : Entity_Id;
New_F : Entity_Id;
begin
if Ekind (Subp) /= Ekind (New_S) then
return False;
end if;
Old_F := Next_Formal (First_Formal (Subp));
New_F := First_Formal (New_S);
while Present (Old_F) and then Present (New_F) loop
if not Conforming_Types (Etype (Old_F), Etype (New_F), Ctyp) then
return False;
end if;
if Ctyp >= Mode_Conformant
and then Ekind (Old_F) /= Ekind (New_F)
then
return False;
end if;
Next_Formal (New_F);
Next_Formal (Old_F);
end loop;
return True;
end Conforms;
-- Start of processing for Analyze_Renamed_Primitive_Operation
begin
if not Is_Overloaded (Selector_Name (Name (N))) then
Old_S := Entity (Selector_Name (Name (N)));
if not Conforms (Old_S, Type_Conformant) then
Old_S := Any_Id;
end if;
else
-- Find the operation that matches the given signature
declare
It : Interp;
Ind : Interp_Index;
begin
Old_S := Any_Id;
Get_First_Interp (Selector_Name (Name (N)), Ind, It);
while Present (It.Nam) loop
if Conforms (It.Nam, Type_Conformant) then
Old_S := It.Nam;
end if;
Get_Next_Interp (Ind, It);
end loop;
end;
end if;
if Old_S = Any_Id then
Error_Msg_N (" no subprogram or entry matches specification", N);
else
if Is_Body then
if not Conforms (Old_S, Subtype_Conformant) then
Error_Msg_N ("subtype conformance error in renaming", N);
end if;
Generate_Reference (New_S, Defining_Entity (N), 'b');
Style.Check_Identifier (Defining_Entity (N), New_S);
else
-- Only mode conformance required for a renaming_as_declaration
if not Conforms (Old_S, Mode_Conformant) then
Error_Msg_N ("mode conformance error in renaming", N);
end if;
-- Enforce the rule given in (RM 6.3.1 (10.1/2)): a prefixed
-- view of a subprogram is intrinsic, because the compiler has
-- to generate a wrapper for any call to it. If the name in a
-- subprogram renaming is a prefixed view, the entity is thus
-- intrinsic, and 'Access cannot be applied to it.
Set_Convention (New_S, Convention_Intrinsic);
end if;
-- Inherit_Renamed_Profile (New_S, Old_S);
-- The prefix can be an arbitrary expression that yields an
-- object, so it must be resolved.
Resolve (Prefix (Name (N)));
end if;
end Analyze_Renamed_Primitive_Operation;
---------------------------------
-- Analyze_Subprogram_Renaming --
---------------------------------
procedure Analyze_Subprogram_Renaming (N : Node_Id) is
Formal_Spec : constant Entity_Id := Corresponding_Formal_Spec (N);
Is_Actual : constant Boolean := Present (Formal_Spec);
Nam : constant Node_Id := Name (N);
Save_AV : constant Ada_Version_Type := Ada_Version;
Save_AVP : constant Node_Id := Ada_Version_Pragma;
Save_AV_Exp : constant Ada_Version_Type := Ada_Version_Explicit;
Spec : constant Node_Id := Specification (N);
Old_S : Entity_Id := Empty;
Rename_Spec : Entity_Id;
procedure Build_Class_Wide_Wrapper
(Ren_Id : out Entity_Id;
Wrap_Id : out Entity_Id);
-- Ada 2012 (AI05-0071): A generic/instance scenario involving a formal
-- type with unknown discriminants and a generic primitive operation of
-- the said type with a box require special processing when the actual
-- is a class-wide type:
--
-- generic
-- type Formal_Typ (<>) is private;
-- with procedure Prim_Op (Param : Formal_Typ) is <>;
-- package Gen is ...
--
-- package Inst is new Gen (Actual_Typ'Class);
--
-- In this case the general renaming mechanism used in the prologue of
-- an instance no longer applies:
--
-- procedure Prim_Op (Param : Formal_Typ) renames Prim_Op;
--
-- The above is replaced the following wrapper/renaming combination:
--
-- procedure Wrapper (Param : Formal_Typ) is -- wrapper
-- begin
-- Prim_Op (Param); -- primitive
-- end Wrapper;
--
-- procedure Prim_Op (Param : Formal_Typ) renames Wrapper;
--
-- This transformation applies only if there is no explicit visible
-- class-wide operation at the point of the instantiation. Ren_Id is
-- the entity of the renaming declaration. Wrap_Id is the entity of
-- the generated class-wide wrapper (or Any_Id).
procedure Check_Null_Exclusion
(Ren : Entity_Id;
Sub : Entity_Id);
-- Ada 2005 (AI-423): Given renaming Ren of subprogram Sub, check the
-- following AI rules:
--
-- If Ren is a renaming of a formal subprogram and one of its
-- parameters has a null exclusion, then the corresponding formal
-- in Sub must also have one. Otherwise the subtype of the Sub's
-- formal parameter must exclude null.
--
-- If Ren is a renaming of a formal function and its return
-- profile has a null exclusion, then Sub's return profile must
-- have one. Otherwise the subtype of Sub's return profile must
-- exclude null.
procedure Freeze_Actual_Profile;
-- In Ada 2012, enforce the freezing rule concerning formal incomplete
-- types: a callable entity freezes its profile, unless it has an
-- incomplete untagged formal (RM 13.14(10.2/3)).
function Has_Class_Wide_Actual return Boolean;
-- Ada 2012 (AI05-071, AI05-0131): True if N is the renaming for a
-- defaulted formal subprogram where the actual for the controlling
-- formal type is class-wide.
function Original_Subprogram (Subp : Entity_Id) return Entity_Id;
-- Find renamed entity when the declaration is a renaming_as_body and
-- the renamed entity may itself be a renaming_as_body. Used to enforce
-- rule that a renaming_as_body is illegal if the declaration occurs
-- before the subprogram it completes is frozen, and renaming indirectly
-- renames the subprogram itself.(Defect Report 8652/0027).
------------------------------
-- Build_Class_Wide_Wrapper --
------------------------------
procedure Build_Class_Wide_Wrapper
(Ren_Id : out Entity_Id;
Wrap_Id : out Entity_Id)
is
Loc : constant Source_Ptr := Sloc (N);
function Build_Call
(Subp_Id : Entity_Id;
Params : List_Id) return Node_Id;
-- Create a dispatching call to invoke routine Subp_Id with actuals
-- built from the parameter specifications of list Params.
function Build_Spec (Subp_Id : Entity_Id) return Node_Id;
-- Create a subprogram specification based on the subprogram profile
-- of Subp_Id.
function Find_Primitive (Typ : Entity_Id) return Entity_Id;
-- Find a primitive subprogram of type Typ which matches the profile
-- of the renaming declaration.
procedure Interpretation_Error (Subp_Id : Entity_Id);
-- Emit a continuation error message suggesting subprogram Subp_Id as
-- a possible interpretation.
function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean;
-- Determine whether subprogram Subp_Id denotes the intrinsic "="
-- operator.
function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean;
-- Determine whether subprogram Subp_Id is a suitable candidate for
-- the role of a wrapped subprogram.
----------------
-- Build_Call --
----------------
function Build_Call
(Subp_Id : Entity_Id;
Params : List_Id) return Node_Id
is
Actuals : constant List_Id := New_List;
Call_Ref : constant Node_Id := New_Occurrence_Of (Subp_Id, Loc);
Formal : Node_Id;
begin
-- Build the actual parameters of the call
Formal := First (Params);
while Present (Formal) loop
Append_To (Actuals,
Make_Identifier (Loc, Chars (Defining_Identifier (Formal))));
Next (Formal);
end loop;
-- Generate:
-- return Subp_Id (Actuals);
if Ekind_In (Subp_Id, E_Function, E_Operator) then
return
Make_Simple_Return_Statement (Loc,
Expression =>
Make_Function_Call (Loc,
Name => Call_Ref,
Parameter_Associations => Actuals));
-- Generate:
-- Subp_Id (Actuals);
else
return
Make_Procedure_Call_Statement (Loc,
Name => Call_Ref,
Parameter_Associations => Actuals);
end if;
end Build_Call;
----------------
-- Build_Spec --
----------------
function Build_Spec (Subp_Id : Entity_Id) return Node_Id is
Params : constant List_Id := Copy_Parameter_List (Subp_Id);
Spec_Id : constant Entity_Id :=
Make_Defining_Identifier (Loc,
Chars => New_External_Name (Chars (Subp_Id), 'R'));
begin
if Ekind (Formal_Spec) = E_Procedure then
return
Make_Procedure_Specification (Loc,
Defining_Unit_Name => Spec_Id,
Parameter_Specifications => Params);
else
return
Make_Function_Specification (Loc,
Defining_Unit_Name => Spec_Id,
Parameter_Specifications => Params,
Result_Definition =>
New_Copy_Tree (Result_Definition (Spec)));
end if;
end Build_Spec;
--------------------
-- Find_Primitive --
--------------------
function Find_Primitive (Typ : Entity_Id) return Entity_Id is
procedure Replace_Parameter_Types (Spec : Node_Id);
-- Given a specification Spec, replace all class-wide parameter
-- types with reference to type Typ.
-----------------------------
-- Replace_Parameter_Types --
-----------------------------
procedure Replace_Parameter_Types (Spec : Node_Id) is
Formal : Node_Id;
Formal_Id : Entity_Id;
Formal_Typ : Node_Id;
begin
Formal := First (Parameter_Specifications (Spec));
while Present (Formal) loop
Formal_Id := Defining_Identifier (Formal);
Formal_Typ := Parameter_Type (Formal);
-- Create a new entity for each class-wide formal to prevent
-- aliasing with the original renaming. Replace the type of
-- such a parameter with the candidate type.
if Nkind (Formal_Typ) = N_Identifier
and then Is_Class_Wide_Type (Etype (Formal_Typ))
then
Set_Defining_Identifier (Formal,
Make_Defining_Identifier (Loc, Chars (Formal_Id)));
Set_Parameter_Type (Formal, New_Occurrence_Of (Typ, Loc));
end if;
Next (Formal);
end loop;
end Replace_Parameter_Types;
-- Local variables
Alt_Ren : constant Node_Id := New_Copy_Tree (N);
Alt_Nam : constant Node_Id := Name (Alt_Ren);
Alt_Spec : constant Node_Id := Specification (Alt_Ren);
Subp_Id : Entity_Id;
-- Start of processing for Find_Primitive
begin
-- Each attempt to find a suitable primitive of a particular type
-- operates on its own copy of the original renaming. As a result
-- the original renaming is kept decoration and side-effect free.
-- Inherit the overloaded status of the renamed subprogram name
if Is_Overloaded (Nam) then
Set_Is_Overloaded (Alt_Nam);
Save_Interps (Nam, Alt_Nam);
end if;
-- The copied renaming is hidden from visibility to prevent the
-- pollution of the enclosing context.
Set_Defining_Unit_Name (Alt_Spec, Make_Temporary (Loc, 'R'));
-- The types of all class-wide parameters must be changed to the
-- candidate type.
Replace_Parameter_Types (Alt_Spec);
-- Try to find a suitable primitive which matches the altered
-- profile of the renaming specification.
Subp_Id :=
Find_Renamed_Entity
(N => Alt_Ren,
Nam => Name (Alt_Ren),
New_S => Analyze_Subprogram_Specification (Alt_Spec),
Is_Actual => Is_Actual);
-- Do not return Any_Id if the resolion of the altered profile
-- failed as this complicates further checks on the caller side,
-- return Empty instead.
if Subp_Id = Any_Id then
return Empty;
else
return Subp_Id;
end if;
end Find_Primitive;
--------------------------
-- Interpretation_Error --
--------------------------
procedure Interpretation_Error (Subp_Id : Entity_Id) is
begin
Error_Msg_Sloc := Sloc (Subp_Id);
if Is_Internal (Subp_Id) then
Error_Msg_NE
("\\possible interpretation: predefined & #",
Spec, Formal_Spec);
else
Error_Msg_NE
("\\possible interpretation: & defined #", Spec, Formal_Spec);
end if;
end Interpretation_Error;
---------------------------
-- Is_Intrinsic_Equality --
---------------------------
function Is_Intrinsic_Equality (Subp_Id : Entity_Id) return Boolean is
begin
return
Ekind (Subp_Id) = E_Operator
and then Chars (Subp_Id) = Name_Op_Eq
and then Is_Intrinsic_Subprogram (Subp_Id);
end Is_Intrinsic_Equality;
---------------------------
-- Is_Suitable_Candidate --
---------------------------
function Is_Suitable_Candidate (Subp_Id : Entity_Id) return Boolean is
begin
if No (Subp_Id) then
return False;
-- An intrinsic subprogram is never a good candidate. This is an
-- indication of a missing primitive, either defined directly or
-- inherited from a parent tagged type.
elsif Is_Intrinsic_Subprogram (Subp_Id) then
return False;
else
return True;
end if;
end Is_Suitable_Candidate;
-- Local variables
Actual_Typ : Entity_Id := Empty;
-- The actual class-wide type for Formal_Typ
CW_Prim_OK : Boolean;
CW_Prim_Op : Entity_Id;
-- The class-wide subprogram (if available) which corresponds to the
-- renamed generic formal subprogram.
Formal_Typ : Entity_Id := Empty;
-- The generic formal type with unknown discriminants
Root_Prim_OK : Boolean;
Root_Prim_Op : Entity_Id;
-- The root type primitive (if available) which corresponds to the
-- renamed generic formal subprogram.
Root_Typ : Entity_Id := Empty;
-- The root type of Actual_Typ
Body_Decl : Node_Id;
Formal : Node_Id;
Prim_Op : Entity_Id;
Spec_Decl : Node_Id;
-- Start of processing for Build_Class_Wide_Wrapper
begin
-- Analyze the specification of the renaming in case the generation
-- of the class-wide wrapper fails.
Ren_Id := Analyze_Subprogram_Specification (Spec);
Wrap_Id := Any_Id;
-- Do not attempt to build a wrapper if the renaming is in error
if Error_Posted (Nam) then
return;
end if;
-- Analyze the renamed name, but do not resolve it. The resolution is
-- completed once a suitable subprogram is found.
Analyze (Nam);
-- When the renamed name denotes the intrinsic operator equals, the
-- name must be treated as overloaded. This allows for a potential
-- match against the root type's predefined equality function.
if Is_Intrinsic_Equality (Entity (Nam)) then
Set_Is_Overloaded (Nam);
Collect_Interps (Nam);
end if;
-- Step 1: Find the generic formal type with unknown discriminants
-- and its corresponding class-wide actual type from the renamed
-- generic formal subprogram.
Formal := First_Formal (Formal_Spec);
while Present (Formal) loop
if Has_Unknown_Discriminants (Etype (Formal))
and then not Is_Class_Wide_Type (Etype (Formal))
and then Is_Class_Wide_Type (Get_Instance_Of (Etype (Formal)))
then
Formal_Typ := Etype (Formal);
Actual_Typ := Get_Instance_Of (Formal_Typ);
Root_Typ := Etype (Actual_Typ);
exit;
end if;
Next_Formal (Formal);
end loop;
-- The specification of the generic formal subprogram should always
-- contain a formal type with unknown discriminants whose actual is
-- a class-wide type, otherwise this indicates a failure in routine
-- Has_Class_Wide_Actual.
pragma Assert (Present (Formal_Typ));
-- Step 2: Find the proper class-wide subprogram or primitive which
-- corresponds to the renamed generic formal subprogram.
CW_Prim_Op := Find_Primitive (Actual_Typ);
CW_Prim_OK := Is_Suitable_Candidate (CW_Prim_Op);
Root_Prim_Op := Find_Primitive (Root_Typ);
Root_Prim_OK := Is_Suitable_Candidate (Root_Prim_Op);
-- The class-wide actual type has two subprograms which correspond to
-- the renamed generic formal subprogram:
-- with procedure Prim_Op (Param : Formal_Typ);
-- procedure Prim_Op (Param : Actual_Typ); -- may be inherited
-- procedure Prim_Op (Param : Actual_Typ'Class);
-- Even though the declaration of the two subprograms is legal, a
-- call to either one is ambiguous and therefore illegal.
if CW_Prim_OK and Root_Prim_OK then
-- A user-defined primitive has precedence over a predefined one
if Is_Internal (CW_Prim_Op)
and then not Is_Internal (Root_Prim_Op)
then
Prim_Op := Root_Prim_Op;
elsif Is_Internal (Root_Prim_Op)
and then not Is_Internal (CW_Prim_Op)
then
Prim_Op := CW_Prim_Op;
elsif CW_Prim_Op = Root_Prim_Op then
Prim_Op := Root_Prim_Op;
-- Otherwise both candidate subprograms are user-defined and
-- ambiguous.
else
Error_Msg_NE
("ambiguous actual for generic subprogram &",
Spec, Formal_Spec);
Interpretation_Error (Root_Prim_Op);
Interpretation_Error (CW_Prim_Op);
return;
end if;
elsif CW_Prim_OK and not Root_Prim_OK then
Prim_Op := CW_Prim_Op;
elsif not CW_Prim_OK and Root_Prim_OK then
Prim_Op := Root_Prim_Op;
-- An intrinsic equality may act as a suitable candidate in the case
-- of a null type extension where the parent's equality is hidden. A
-- call to an intrinsic equality is expanded as dispatching.
elsif Present (Root_Prim_Op)
and then Is_Intrinsic_Equality (Root_Prim_Op)
then
Prim_Op := Root_Prim_Op;
-- Otherwise there are no candidate subprograms. Let the caller
-- diagnose the error.
else
return;
end if;
-- At this point resolution has taken place and the name is no longer
-- overloaded. Mark the primitive as referenced.
Set_Is_Overloaded (Name (N), False);
Set_Referenced (Prim_Op);
-- Step 3: Create the declaration and the body of the wrapper, insert
-- all the pieces into the tree.
Spec_Decl :=
Make_Subprogram_Declaration (Loc,
Specification => Build_Spec (Ren_Id));
Insert_Before_And_Analyze (N, Spec_Decl);
-- If the operator carries an Eliminated pragma, indicate that the
-- wrapper is also to be eliminated, to prevent spurious error when
-- using gnatelim on programs that include box-initialization of
-- equality operators.
Wrap_Id := Defining_Entity (Spec_Decl);
Set_Is_Eliminated (Wrap_Id, Is_Eliminated (Prim_Op));
Body_Decl :=
Make_Subprogram_Body (Loc,
Specification => Build_Spec (Ren_Id),
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Build_Call
(Subp_Id => Prim_Op,
Params =>
Parameter_Specifications
(Specification (Spec_Decl))))));
-- The generated body does not freeze and must be analyzed when the
-- class-wide wrapper is frozen. The body is only needed if expansion
-- is enabled.
if Expander_Active then
Append_Freeze_Action (Wrap_Id, Body_Decl);
end if;
-- Step 4: The subprogram renaming aliases the wrapper
Rewrite (Nam, New_Occurrence_Of (Wrap_Id, Loc));
end Build_Class_Wide_Wrapper;
--------------------------
-- Check_Null_Exclusion --
--------------------------
procedure Check_Null_Exclusion
(Ren : Entity_Id;
Sub : Entity_Id)
is
Ren_Formal : Entity_Id;
Sub_Formal : Entity_Id;
begin
-- Parameter check
Ren_Formal := First_Formal (Ren);
Sub_Formal := First_Formal (Sub);
while Present (Ren_Formal) and then Present (Sub_Formal) loop
if Has_Null_Exclusion (Parent (Ren_Formal))
and then
not (Has_Null_Exclusion (Parent (Sub_Formal))
or else Can_Never_Be_Null (Etype (Sub_Formal)))
then
Error_Msg_NE
("`NOT NULL` required for parameter &",
Parent (Sub_Formal), Sub_Formal);
end if;
Next_Formal (Ren_Formal);
Next_Formal (Sub_Formal);
end loop;
-- Return profile check
if Nkind (Parent (Ren)) = N_Function_Specification
and then Nkind (Parent (Sub)) = N_Function_Specification
and then Has_Null_Exclusion (Parent (Ren))
and then not (Has_Null_Exclusion (Parent (Sub))
or else Can_Never_Be_Null (Etype (Sub)))
then
Error_Msg_N
("return must specify `NOT NULL`",
Result_Definition (Parent (Sub)));
end if;
end Check_Null_Exclusion;
---------------------------
-- Freeze_Actual_Profile --
---------------------------
procedure Freeze_Actual_Profile is
F : Entity_Id;
Has_Untagged_Inc : Boolean;
Instantiation_Node : constant Node_Id := Parent (N);
begin
if Ada_Version >= Ada_2012 then
F := First_Formal (Formal_Spec);
Has_Untagged_Inc := False;
while Present (F) loop
if Ekind (Etype (F)) = E_Incomplete_Type
and then not Is_Tagged_Type (Etype (F))
then
Has_Untagged_Inc := True;
exit;
end if;
F := Next_Formal (F);
end loop;
if Ekind (Formal_Spec) = E_Function
and then Ekind (Etype (Formal_Spec)) = E_Incomplete_Type
and then not Is_Tagged_Type (Etype (F))
then
Has_Untagged_Inc := True;
end if;
if not Has_Untagged_Inc then
F := First_Formal (Old_S);
while Present (F) loop
Freeze_Before (Instantiation_Node, Etype (F));
if Is_Incomplete_Or_Private_Type (Etype (F))
and then No (Underlying_Type (Etype (F)))
then
-- Exclude generic types, or types derived from them.
-- They will be frozen in the enclosing instance.
if Is_Generic_Type (Etype (F))
or else Is_Generic_Type (Root_Type (Etype (F)))
then
null;
else
Error_Msg_NE
("type& must be frozen before this point",
Instantiation_Node, Etype (F));
end if;
end if;
F := Next_Formal (F);
end loop;
end if;
end if;
end Freeze_Actual_Profile;
---------------------------
-- Has_Class_Wide_Actual --
---------------------------
function Has_Class_Wide_Actual return Boolean is
Formal : Entity_Id;
Formal_Typ : Entity_Id;
begin
if Is_Actual then
Formal := First_Formal (Formal_Spec);
while Present (Formal) loop
Formal_Typ := Etype (Formal);
if Has_Unknown_Discriminants (Formal_Typ)
and then not Is_Class_Wide_Type (Formal_Typ)
and then Is_Class_Wide_Type (Get_Instance_Of (Formal_Typ))
then
return True;
end if;
Next_Formal (Formal);
end loop;
end if;
return False;
end Has_Class_Wide_Actual;
-------------------------
-- Original_Subprogram --
-------------------------
function Original_Subprogram (Subp : Entity_Id) return Entity_Id is
Orig_Decl : Node_Id;
Orig_Subp : Entity_Id;
begin
-- First case: renamed entity is itself a renaming
if Present (Alias (Subp)) then
return Alias (Subp);
elsif Nkind (Unit_Declaration_Node (Subp)) = N_Subprogram_Declaration
and then Present (Corresponding_Body (Unit_Declaration_Node (Subp)))
then
-- Check if renamed entity is a renaming_as_body
Orig_Decl :=
Unit_Declaration_Node
(Corresponding_Body (Unit_Declaration_Node (Subp)));
if Nkind (Orig_Decl) = N_Subprogram_Renaming_Declaration then
Orig_Subp := Entity (Name (Orig_Decl));
if Orig_Subp = Rename_Spec then
-- Circularity detected
return Orig_Subp;
else
return (Original_Subprogram (Orig_Subp));
end if;
else
return Subp;
end if;
else
return Subp;
end if;
end Original_Subprogram;
-- Local variables
CW_Actual : constant Boolean := Has_Class_Wide_Actual;
-- Ada 2012 (AI05-071, AI05-0131): True if the renaming is for a
-- defaulted formal subprogram when the actual for a related formal
-- type is class-wide.
Inst_Node : Node_Id := Empty;
New_S : Entity_Id;
-- Start of processing for Analyze_Subprogram_Renaming
begin
-- The subprogram renaming declaration may be subject to pragma Ghost
-- with policy Ignore. Set the mode now to ensure that any nodes
-- generated during analysis and expansion are properly flagged as
-- ignored Ghost.
Set_Ghost_Mode (N);
-- We must test for the attribute renaming case before the Analyze
-- call because otherwise Sem_Attr will complain that the attribute
-- is missing an argument when it is analyzed.
if Nkind (Nam) = N_Attribute_Reference then
-- In the case of an abstract formal subprogram association, rewrite
-- an actual given by a stream attribute as the name of the
-- corresponding stream primitive of the type.
-- In a generic context the stream operations are not generated, and
-- this must be treated as a normal attribute reference, to be
-- expanded in subsequent instantiations.
if Is_Actual
and then Is_Abstract_Subprogram (Formal_Spec)
and then Expander_Active
then
declare
Stream_Prim : Entity_Id;
Prefix_Type : constant Entity_Id := Entity (Prefix (Nam));
begin
-- The class-wide forms of the stream attributes are not
-- primitive dispatching operations (even though they
-- internally dispatch to a stream attribute).
if Is_Class_Wide_Type (Prefix_Type) then
Error_Msg_N
("attribute must be a primitive dispatching operation",
Nam);
return;
end if;
-- Retrieve the primitive subprogram associated with the
-- attribute. This can only be a stream attribute, since those
-- are the only ones that are dispatching (and the actual for
-- an abstract formal subprogram must be dispatching
-- operation).
begin
case Attribute_Name (Nam) is
when Name_Input =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Input);
when Name_Output =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Output);
when Name_Read =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Read);
when Name_Write =>
Stream_Prim :=
Find_Prim_Op (Prefix_Type, TSS_Stream_Write);
when others =>
Error_Msg_N
("attribute must be a primitive"
& " dispatching operation", Nam);
return;
end case;
exception
-- If no operation was found, and the type is limited,
-- the user should have defined one.
when Program_Error =>
if Is_Limited_Type (Prefix_Type) then
Error_Msg_NE
("stream operation not defined for type&",
N, Prefix_Type);
return;
-- Otherwise, compiler should have generated default
else
raise;
end if;
end;
-- Rewrite the attribute into the name of its corresponding
-- primitive dispatching subprogram. We can then proceed with
-- the usual processing for subprogram renamings.
declare
Prim_Name : constant Node_Id :=
Make_Identifier (Sloc (Nam),
Chars => Chars (Stream_Prim));
begin
Set_Entity (Prim_Name, Stream_Prim);
Rewrite (Nam, Prim_Name);
Analyze (Nam);
end;
end;
-- Normal processing for a renaming of an attribute
else
Attribute_Renaming (N);
return;
end if;
end if;
-- Check whether this declaration corresponds to the instantiation
-- of a formal subprogram.
-- If this is an instantiation, the corresponding actual is frozen and
-- error messages can be made more precise. If this is a default
-- subprogram, the entity is already established in the generic, and is
-- not retrieved by visibility. If it is a default with a box, the
-- candidate interpretations, if any, have been collected when building
-- the renaming declaration. If overloaded, the proper interpretation is
-- determined in Find_Renamed_Entity. If the entity is an operator,
-- Find_Renamed_Entity applies additional visibility checks.
if Is_Actual then
Inst_Node := Unit_Declaration_Node (Formal_Spec);
-- Check whether the renaming is for a defaulted actual subprogram
-- with a class-wide actual.
-- The class-wide wrapper is not needed in GNATprove_Mode and there
-- is an external axiomatization on the package.
if CW_Actual
and then Box_Present (Inst_Node)
and then not
(GNATprove_Mode
and then
Present (Containing_Package_With_Ext_Axioms (Formal_Spec)))
then
Build_Class_Wide_Wrapper (New_S, Old_S);
elsif Is_Entity_Name (Nam)
and then Present (Entity (Nam))
and then not Comes_From_Source (Nam)
and then not Is_Overloaded (Nam)
then
Old_S := Entity (Nam);
New_S := Analyze_Subprogram_Specification (Spec);
-- Operator case
if Ekind (Entity (Nam)) = E_Operator then
-- Box present
if Box_Present (Inst_Node) then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
-- If there is an immediately visible homonym of the operator
-- and the declaration has a default, this is worth a warning
-- because the user probably did not intend to get the pre-
-- defined operator, visible in the generic declaration. To
-- find if there is an intended candidate, analyze the renaming
-- again in the current context.
elsif Scope (Old_S) = Standard_Standard
and then Present (Default_Name (Inst_Node))
then
declare
Decl : constant Node_Id := New_Copy_Tree (N);
Hidden : Entity_Id;
begin
Set_Entity (Name (Decl), Empty);
Analyze (Name (Decl));
Hidden :=
Find_Renamed_Entity (Decl, Name (Decl), New_S, True);
if Present (Hidden)
and then In_Open_Scopes (Scope (Hidden))
and then Is_Immediately_Visible (Hidden)
and then Comes_From_Source (Hidden)
and then Hidden /= Old_S
then
Error_Msg_Sloc := Sloc (Hidden);
Error_Msg_N ("default subprogram is resolved " &
"in the generic declaration " &
"(RM 12.6(17))??", N);
Error_Msg_NE ("\and will not use & #??", N, Hidden);
end if;
end;
end if;
end if;
else
Analyze (Nam);
New_S := Analyze_Subprogram_Specification (Spec);
end if;
else
-- Renamed entity must be analyzed first, to avoid being hidden by
-- new name (which might be the same in a generic instance).
Analyze (Nam);
-- The renaming defines a new overloaded entity, which is analyzed
-- like a subprogram declaration.
New_S := Analyze_Subprogram_Specification (Spec);
end if;
if Current_Scope /= Standard_Standard then
Set_Is_Pure (New_S, Is_Pure (Current_Scope));
end if;
-- Set SPARK mode from current context
Set_SPARK_Pragma (New_S, SPARK_Mode_Pragma);
Set_SPARK_Pragma_Inherited (New_S, True);
Rename_Spec := Find_Corresponding_Spec (N);
-- Case of Renaming_As_Body
if Present (Rename_Spec) then
-- Renaming declaration is the completion of the declaration of
-- Rename_Spec. We build an actual body for it at the freezing point.
Set_Corresponding_Spec (N, Rename_Spec);
-- Deal with special case of stream functions of abstract types
-- and interfaces.
if Nkind (Unit_Declaration_Node (Rename_Spec)) =
N_Abstract_Subprogram_Declaration
then
-- Input stream functions are abstract if the object type is
-- abstract. Similarly, all default stream functions for an
-- interface type are abstract. However, these subprograms may
-- receive explicit declarations in representation clauses, making
-- the attribute subprograms usable as defaults in subsequent
-- type extensions.
-- In this case we rewrite the declaration to make the subprogram
-- non-abstract. We remove the previous declaration, and insert
-- the new one at the point of the renaming, to prevent premature
-- access to unfrozen types. The new declaration reuses the
-- specification of the previous one, and must not be analyzed.
pragma Assert
(Is_Primitive (Entity (Nam))
and then
Is_Abstract_Type (Find_Dispatching_Type (Entity (Nam))));
declare
Old_Decl : constant Node_Id :=
Unit_Declaration_Node (Rename_Spec);
New_Decl : constant Node_Id :=
Make_Subprogram_Declaration (Sloc (N),
Specification =>
Relocate_Node (Specification (Old_Decl)));
begin
Remove (Old_Decl);
Insert_After (N, New_Decl);
Set_Is_Abstract_Subprogram (Rename_Spec, False);
Set_Analyzed (New_Decl);
end;
end if;
Set_Corresponding_Body (Unit_Declaration_Node (Rename_Spec), New_S);
if Ada_Version = Ada_83 and then Comes_From_Source (N) then
Error_Msg_N ("(Ada 83) renaming cannot serve as a body", N);
end if;
Set_Convention (New_S, Convention (Rename_Spec));
Check_Fully_Conformant (New_S, Rename_Spec);
Set_Public_Status (New_S);
-- The specification does not introduce new formals, but only
-- repeats the formals of the original subprogram declaration.
-- For cross-reference purposes, and for refactoring tools, we
-- treat the formals of the renaming declaration as body formals.
Reference_Body_Formals (Rename_Spec, New_S);
-- Indicate that the entity in the declaration functions like the
-- corresponding body, and is not a new entity. The body will be
-- constructed later at the freeze point, so indicate that the
-- completion has not been seen yet.
Set_Ekind (New_S, E_Subprogram_Body);
New_S := Rename_Spec;
Set_Has_Completion (Rename_Spec, False);
-- Ada 2005: check overriding indicator
if Present (Overridden_Operation (Rename_Spec)) then
if Must_Not_Override (Specification (N)) then
Error_Msg_NE
("subprogram& overrides inherited operation",
N, Rename_Spec);
elsif
Style_Check and then not Must_Override (Specification (N))
then
Style.Missing_Overriding (N, Rename_Spec);
end if;
elsif Must_Override (Specification (N)) then
Error_Msg_NE ("subprogram& is not overriding", N, Rename_Spec);
end if;
-- Normal subprogram renaming (not renaming as body)
else
Generate_Definition (New_S);
New_Overloaded_Entity (New_S);
if Is_Entity_Name (Nam)
and then Is_Intrinsic_Subprogram (Entity (Nam))
then
null;
else
Check_Delayed_Subprogram (New_S);
end if;
end if;
-- There is no need for elaboration checks on the new entity, which may
-- be called before the next freezing point where the body will appear.
-- Elaboration checks refer to the real entity, not the one created by
-- the renaming declaration.
Set_Kill_Elaboration_Checks (New_S, True);
-- If we had a previous error, indicate a completely is present to stop
-- junk cascaded messages, but don't take any further action.
if Etype (Nam) = Any_Type then
Set_Has_Completion (New_S);
return;
-- Case where name has the form of a selected component
elsif Nkind (Nam) = N_Selected_Component then
-- A name which has the form A.B can designate an entry of task A, a
-- protected operation of protected object A, or finally a primitive
-- operation of object A. In the later case, A is an object of some
-- tagged type, or an access type that denotes one such. To further
-- distinguish these cases, note that the scope of a task entry or
-- protected operation is type of the prefix.
-- The prefix could be an overloaded function call that returns both
-- kinds of operations. This overloading pathology is left to the
-- dedicated reader ???
declare
T : constant Entity_Id := Etype (Prefix (Nam));
begin
if Present (T)
and then
(Is_Tagged_Type (T)
or else
(Is_Access_Type (T)
and then Is_Tagged_Type (Designated_Type (T))))
and then Scope (Entity (Selector_Name (Nam))) /= T
then
Analyze_Renamed_Primitive_Operation
(N, New_S, Present (Rename_Spec));
return;
else
-- Renamed entity is an entry or protected operation. For those
-- cases an explicit body is built (at the point of freezing of
-- this entity) that contains a call to the renamed entity.
-- This is not allowed for renaming as body if the renamed
-- spec is already frozen (see RM 8.5.4(5) for details).
if Present (Rename_Spec) and then Is_Frozen (Rename_Spec) then
Error_Msg_N
("renaming-as-body cannot rename entry as subprogram", N);
Error_Msg_NE
("\since & is already frozen (RM 8.5.4(5))",
N, Rename_Spec);
else
Analyze_Renamed_Entry (N, New_S, Present (Rename_Spec));
end if;
return;
end if;
end;
-- Case where name is an explicit dereference X.all
elsif Nkind (Nam) = N_Explicit_Dereference then
-- Renamed entity is designated by access_to_subprogram expression.
-- Must build body to encapsulate call, as in the entry case.
Analyze_Renamed_Dereference (N, New_S, Present (Rename_Spec));
return;
-- Indexed component
elsif Nkind (Nam) = N_Indexed_Component then
Analyze_Renamed_Family_Member (N, New_S, Present (Rename_Spec));
return;
-- Character literal
elsif Nkind (Nam) = N_Character_Literal then
Analyze_Renamed_Character (N, New_S, Present (Rename_Spec));
return;
-- Only remaining case is where we have a non-entity name, or a renaming
-- of some other non-overloadable entity.
elsif not Is_Entity_Name (Nam)
or else not Is_Overloadable (Entity (Nam))
then
-- Do not mention the renaming if it comes from an instance
if not Is_Actual then
Error_Msg_N ("expect valid subprogram name in renaming", N);
else
Error_Msg_NE ("no visible subprogram for formal&", N, Nam);
end if;
return;
end if;
-- Find the renamed entity that matches the given specification. Disable
-- Ada_83 because there is no requirement of full conformance between
-- renamed entity and new entity, even though the same circuit is used.
-- This is a bit of an odd case, which introduces a really irregular use
-- of Ada_Version[_Explicit]. Would be nice to find cleaner way to do
-- this. ???
Ada_Version := Ada_Version_Type'Max (Ada_Version, Ada_95);
Ada_Version_Pragma := Empty;
Ada_Version_Explicit := Ada_Version;
if No (Old_S) then
Old_S := Find_Renamed_Entity (N, Name (N), New_S, Is_Actual);
-- The visible operation may be an inherited abstract operation that
-- was overridden in the private part, in which case a call will
-- dispatch to the overriding operation. Use the overriding one in
-- the renaming declaration, to prevent spurious errors below.
if Is_Overloadable (Old_S)
and then Is_Abstract_Subprogram (Old_S)
and then No (DTC_Entity (Old_S))
and then Present (Alias (Old_S))
and then not Is_Abstract_Subprogram (Alias (Old_S))
and then Present (Overridden_Operation (Alias (Old_S)))
then
Old_S := Alias (Old_S);
end if;
-- When the renamed subprogram is overloaded and used as an actual
-- of a generic, its entity is set to the first available homonym.
-- We must first disambiguate the name, then set the proper entity.
if Is_Actual and then Is_Overloaded (Nam) then
Set_Entity (Nam, Old_S);
end if;
end if;
-- Most common case: subprogram renames subprogram. No body is generated
-- in this case, so we must indicate the declaration is complete as is.
-- and inherit various attributes of the renamed subprogram.
if No (Rename_Spec) then
Set_Has_Completion (New_S);
Set_Is_Imported (New_S, Is_Imported (Entity (Nam)));
Set_Is_Pure (New_S, Is_Pure (Entity (Nam)));
Set_Is_Preelaborated (New_S, Is_Preelaborated (Entity (Nam)));
-- A subprogram renaming is Ghost if the renamed entity is Ghost or
-- the construct appears within a Ghost scope.
if Is_Ghost_Entity (Entity (Nam)) or else Ghost_Mode > None then
Set_Is_Ghost_Entity (New_S);
end if;
-- Ada 2005 (AI-423): Check the consistency of null exclusions
-- between a subprogram and its correct renaming.
-- Note: the Any_Id check is a guard that prevents compiler crashes
-- when performing a null exclusion check between a renaming and a
-- renamed subprogram that has been found to be illegal.
if Ada_Version >= Ada_2005 and then Entity (Nam) /= Any_Id then
Check_Null_Exclusion
(Ren => New_S,
Sub => Entity (Nam));
end if;
-- Enforce the Ada 2005 rule that the renamed entity cannot require
-- overriding. The flag Requires_Overriding is set very selectively
-- and misses some other illegal cases. The additional conditions
-- checked below are sufficient but not necessary ???
-- The rule does not apply to the renaming generated for an actual
-- subprogram in an instance.
if Is_Actual then
null;
-- Guard against previous errors, and omit renamings of predefined
-- operators.
elsif not Ekind_In (Old_S, E_Function, E_Procedure) then
null;
elsif Requires_Overriding (Old_S)
or else
(Is_Abstract_Subprogram (Old_S)
and then Present (Find_Dispatching_Type (Old_S))
and then
not Is_Abstract_Type (Find_Dispatching_Type (Old_S)))
then
Error_Msg_N
("renamed entity cannot be "
& "subprogram that requires overriding (RM 8.5.4 (5.1))", N);
end if;
end if;
if Old_S /= Any_Id then
if Is_Actual and then From_Default (N) then
-- This is an implicit reference to the default actual
Generate_Reference (Old_S, Nam, Typ => 'i', Force => True);
else
Generate_Reference (Old_S, Nam);
end if;
Check_Internal_Protected_Use (N, Old_S);
-- For a renaming-as-body, require subtype conformance, but if the
-- declaration being completed has not been frozen, then inherit the
-- convention of the renamed subprogram prior to checking conformance
-- (unless the renaming has an explicit convention established; the
-- rule stated in the RM doesn't seem to address this ???).
if Present (Rename_Spec) then
Generate_Reference (Rename_Spec, Defining_Entity (Spec), 'b');
Style.Check_Identifier (Defining_Entity (Spec), Rename_Spec);
if not Is_Frozen (Rename_Spec) then
if not Has_Convention_Pragma (Rename_Spec) then
Set_Convention (New_S, Convention (Old_S));
end if;
if Ekind (Old_S) /= E_Operator then
Check_Mode_Conformant (New_S, Old_S, Spec);
end if;
if Original_Subprogram (Old_S) = Rename_Spec then
Error_Msg_N ("unfrozen subprogram cannot rename itself ", N);
end if;
else
Check_Subtype_Conformant (New_S, Old_S, Spec);
end if;
Check_Frozen_Renaming (N, Rename_Spec);
-- Check explicitly that renamed entity is not intrinsic, because
-- in a generic the renamed body is not built. In this case,
-- the renaming_as_body is a completion.
if Inside_A_Generic then
if Is_Frozen (Rename_Spec)
and then Is_Intrinsic_Subprogram (Old_S)
then
Error_Msg_N
("subprogram in renaming_as_body cannot be intrinsic",
Name (N));
end if;
Set_Has_Completion (Rename_Spec);
end if;
elsif Ekind (Old_S) /= E_Operator then
-- If this a defaulted subprogram for a class-wide actual there is
-- no check for mode conformance, given that the signatures don't
-- match (the source mentions T but the actual mentions T'Class).
if CW_Actual then
null;
elsif not Is_Actual or else No (Enclosing_Instance) then
Check_Mode_Conformant (New_S, Old_S);
end if;
if Is_Actual and then Error_Posted (New_S) then
Error_Msg_NE ("invalid actual subprogram: & #!", N, Old_S);
end if;
end if;
if No (Rename_Spec) then
-- The parameter profile of the new entity is that of the renamed
-- entity: the subtypes given in the specification are irrelevant.
Inherit_Renamed_Profile (New_S, Old_S);
-- A call to the subprogram is transformed into a call to the
-- renamed entity. This is transitive if the renamed entity is
-- itself a renaming.
if Present (Alias (Old_S)) then
Set_Alias (New_S, Alias (Old_S));
else
Set_Alias (New_S, Old_S);
end if;
-- Note that we do not set Is_Intrinsic_Subprogram if we have a
-- renaming as body, since the entity in this case is not an
-- intrinsic (it calls an intrinsic, but we have a real body for
-- this call, and it is in this body that the required intrinsic
-- processing will take place).
-- Also, if this is a renaming of inequality, the renamed operator
-- is intrinsic, but what matters is the corresponding equality
-- operator, which may be user-defined.
Set_Is_Intrinsic_Subprogram
(New_S,
Is_Intrinsic_Subprogram (Old_S)
and then
(Chars (Old_S) /= Name_Op_Ne
or else Ekind (Old_S) = E_Operator
or else Is_Intrinsic_Subprogram
(Corresponding_Equality (Old_S))));
if Ekind (Alias (New_S)) = E_Operator then
Set_Has_Delayed_Freeze (New_S, False);
end if;
-- If the renaming corresponds to an association for an abstract
-- formal subprogram, then various attributes must be set to
-- indicate that the renaming is an abstract dispatching operation
-- with a controlling type.
if Is_Actual and then Is_Abstract_Subprogram (Formal_Spec) then
-- Mark the renaming as abstract here, so Find_Dispatching_Type
-- see it as corresponding to a generic association for a
-- formal abstract subprogram
Set_Is_Abstract_Subprogram (New_S);
declare
New_S_Ctrl_Type : constant Entity_Id :=
Find_Dispatching_Type (New_S);
Old_S_Ctrl_Type : constant Entity_Id :=
Find_Dispatching_Type (Old_S);
begin
if Old_S_Ctrl_Type /= New_S_Ctrl_Type then
Error_Msg_NE
("actual must be dispatching subprogram for type&",
Nam, New_S_Ctrl_Type);
else
Set_Is_Dispatching_Operation (New_S);
Check_Controlling_Formals (New_S_Ctrl_Type, New_S);
-- If the actual in the formal subprogram is itself a
-- formal abstract subprogram association, there's no
-- dispatch table component or position to inherit.
if Present (DTC_Entity (Old_S)) then
Set_DTC_Entity (New_S, DTC_Entity (Old_S));
Set_DT_Position_Value (New_S, DT_Position (Old_S));
end if;
end if;
end;
end if;
end if;
if Is_Actual then
null;
-- The following is illegal, because F hides whatever other F may
-- be around:
-- function F (...) renames F;
elsif Old_S = New_S
or else (Nkind (Nam) /= N_Expanded_Name
and then Chars (Old_S) = Chars (New_S))
then
Error_Msg_N ("subprogram cannot rename itself", N);
-- This is illegal even if we use a selector:
-- function F (...) renames Pkg.F;
-- because F is still hidden.
elsif Nkind (Nam) = N_Expanded_Name
and then Entity (Prefix (Nam)) = Current_Scope
and then Chars (Selector_Name (Nam)) = Chars (New_S)
then
-- This is an error, but we overlook the error and accept the
-- renaming if the special Overriding_Renamings mode is in effect.
if not Overriding_Renamings then
Error_Msg_NE
("implicit operation& is not visible (RM 8.3 (15))",
Nam, Old_S);
end if;
end if;
Set_Convention (New_S, Convention (Old_S));
if Is_Abstract_Subprogram (Old_S) then
if Present (Rename_Spec) then
Error_Msg_N
("a renaming-as-body cannot rename an abstract subprogram",
N);
Set_Has_Completion (Rename_Spec);
else
Set_Is_Abstract_Subprogram (New_S);
end if;
end if;
Check_Library_Unit_Renaming (N, Old_S);
-- Pathological case: procedure renames entry in the scope of its
-- task. Entry is given by simple name, but body must be built for
-- procedure. Of course if called it will deadlock.
if Ekind (Old_S) = E_Entry then
Set_Has_Completion (New_S, False);
Set_Alias (New_S, Empty);
end if;
if Is_Actual then
Freeze_Before (N, Old_S);
Freeze_Actual_Profile;
Set_Has_Delayed_Freeze (New_S, False);
Freeze_Before (N, New_S);
-- An abstract subprogram is only allowed as an actual in the case
-- where the formal subprogram is also abstract.
if (Ekind (Old_S) = E_Procedure or else Ekind (Old_S) = E_Function)
and then Is_Abstract_Subprogram (Old_S)
and then not Is_Abstract_Subprogram (Formal_Spec)
then
Error_Msg_N
("abstract subprogram not allowed as generic actual", Nam);
end if;
end if;
else
-- A common error is to assume that implicit operators for types are
-- defined in Standard, or in the scope of a subtype. In those cases
-- where the renamed entity is given with an expanded name, it is
-- worth mentioning that operators for the type are not declared in
-- the scope given by the prefix.
if Nkind (Nam) = N_Expanded_Name
and then Nkind (Selector_Name (Nam)) = N_Operator_Symbol
and then Scope (Entity (Nam)) = Standard_Standard
then
declare
T : constant Entity_Id :=
Base_Type (Etype (First_Formal (New_S)));
begin
Error_Msg_Node_2 := Prefix (Nam);
Error_Msg_NE
("operator for type& is not declared in&", Prefix (Nam), T);
end;
else
Error_Msg_NE
("no visible subprogram matches the specification for&",
Spec, New_S);
end if;
if Present (Candidate_Renaming) then
declare
F1 : Entity_Id;
F2 : Entity_Id;
T1 : Entity_Id;
begin
F1 := First_Formal (Candidate_Renaming);
F2 := First_Formal (New_S);
T1 := First_Subtype (Etype (F1));
while Present (F1) and then Present (F2) loop
Next_Formal (F1);
Next_Formal (F2);
end loop;
if Present (F1) and then Present (Default_Value (F1)) then
if Present (Next_Formal (F1)) then
Error_Msg_NE
("\missing specification for &" &
" and other formals with defaults", Spec, F1);
else
Error_Msg_NE
("\missing specification for &", Spec, F1);
end if;
end if;
if Nkind (Nam) = N_Operator_Symbol
and then From_Default (N)
then
Error_Msg_Node_2 := T1;
Error_Msg_NE
("default & on & is not directly visible",
Nam, Nam);
end if;
end;
end if;
end if;
-- Ada 2005 AI 404: if the new subprogram is dispatching, verify that
-- controlling access parameters are known non-null for the renamed
-- subprogram. Test also applies to a subprogram instantiation that
-- is dispatching. Test is skipped if some previous error was detected
-- that set Old_S to Any_Id.
if Ada_Version >= Ada_2005
and then Old_S /= Any_Id
and then not Is_Dispatching_Operation (Old_S)
and then Is_Dispatching_Operation (New_S)
then
declare
Old_F : Entity_Id;
New_F : Entity_Id;
begin
Old_F := First_Formal (Old_S);
New_F := First_Formal (New_S);
while Present (Old_F) loop
if Ekind (Etype (Old_F)) = E_Anonymous_Access_Type
and then Is_Controlling_Formal (New_F)
and then not Can_Never_Be_Null (Old_F)
then
Error_Msg_N ("access parameter is controlling,", New_F);
Error_Msg_NE
("\corresponding parameter of& "
& "must be explicitly null excluding", New_F, Old_S);
end if;
Next_Formal (Old_F);
Next_Formal (New_F);
end loop;
end;
end if;
-- A useful warning, suggested by Ada Bug Finder (Ada-Europe 2005)
-- is to warn if an operator is being renamed as a different operator.
-- If the operator is predefined, examine the kind of the entity, not
-- the abbreviated declaration in Standard.
if Comes_From_Source (N)
and then Present (Old_S)
and then (Nkind (Old_S) = N_Defining_Operator_Symbol
or else Ekind (Old_S) = E_Operator)
and then Nkind (New_S) = N_Defining_Operator_Symbol
and then Chars (Old_S) /= Chars (New_S)
then
Error_Msg_NE
("& is being renamed as a different operator??", N, Old_S);
end if;
-- Check for renaming of obsolescent subprogram
Check_Obsolescent_2005_Entity (Entity (Nam), Nam);
-- Another warning or some utility: if the new subprogram as the same
-- name as the old one, the old one is not hidden by an outer homograph,
-- the new one is not a public symbol, and the old one is otherwise
-- directly visible, the renaming is superfluous.
if Chars (Old_S) = Chars (New_S)
and then Comes_From_Source (N)
and then Scope (Old_S) /= Standard_Standard
and then Warn_On_Redundant_Constructs
and then (Is_Immediately_Visible (Old_S)
or else Is_Potentially_Use_Visible (Old_S))
and then Is_Overloadable (Current_Scope)
and then Chars (Current_Scope) /= Chars (Old_S)
then
Error_Msg_N
("redundant renaming, entity is directly visible?r?", Name (N));
end if;
-- Implementation-defined aspect specifications can appear in a renaming
-- declaration, but not language-defined ones. The call to procedure
-- Analyze_Aspect_Specifications will take care of this error check.
if Has_Aspects (N) then
Analyze_Aspect_Specifications (N, New_S);
end if;
Ada_Version := Save_AV;
Ada_Version_Pragma := Save_AVP;
Ada_Version_Explicit := Save_AV_Exp;
-- In GNATprove mode, the renamings of actual subprograms are replaced
-- with wrapper functions that make it easier to propagate axioms to the
-- points of call within an instance. Wrappers are generated if formal
-- subprogram is subject to axiomatization.
-- The types in the wrapper profiles are obtained from (instances of)
-- the types of the formal subprogram.
if Is_Actual
and then GNATprove_Mode
and then Present (Containing_Package_With_Ext_Axioms (Formal_Spec))
and then not Inside_A_Generic
then
if Ekind (Old_S) = E_Function then
Rewrite (N, Build_Function_Wrapper (Formal_Spec, Old_S));
Analyze (N);
elsif Ekind (Old_S) = E_Operator then
Rewrite (N, Build_Operator_Wrapper (Formal_Spec, Old_S));
Analyze (N);
end if;
end if;
end Analyze_Subprogram_Renaming;
-------------------------
-- Analyze_Use_Package --
-------------------------
-- Resolve the package names in the use clause, and make all the visible
-- entities defined in the package potentially use-visible. If the package
-- is already in use from a previous use clause, its visible entities are
-- already use-visible. In that case, mark the occurrence as a redundant
-- use. If the package is an open scope, i.e. if the use clause occurs
-- within the package itself, ignore it.
procedure Analyze_Use_Package (N : Node_Id) is
Pack_Name : Node_Id;
Pack : Entity_Id;
-- Start of processing for Analyze_Use_Package
begin
Check_SPARK_05_Restriction ("use clause is not allowed", N);
Set_Hidden_By_Use_Clause (N, No_Elist);
-- Use clause not allowed in a spec of a predefined package declaration
-- except that packages whose file name starts a-n are OK (these are
-- children of Ada.Numerics, which are never loaded by Rtsfind).
if Is_Predefined_File_Name (Unit_File_Name (Current_Sem_Unit))
and then Name_Buffer (1 .. 3) /= "a-n"
and then
Nkind (Unit (Cunit (Current_Sem_Unit))) = N_Package_Declaration
then
Error_Msg_N ("use clause not allowed in predefined spec", N);
end if;
-- Chain clause to list of use clauses in current scope
if Nkind (Parent (N)) /= N_Compilation_Unit then
Chain_Use_Clause (N);
end if;
-- Loop through package names to identify referenced packages
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
Analyze (Pack_Name);
if Nkind (Parent (N)) = N_Compilation_Unit
and then Nkind (Pack_Name) = N_Expanded_Name
then
declare
Pref : Node_Id;
begin
Pref := Prefix (Pack_Name);
while Nkind (Pref) = N_Expanded_Name loop
Pref := Prefix (Pref);
end loop;
if Entity (Pref) = Standard_Standard then
Error_Msg_N
("predefined package Standard cannot appear"
& " in a context clause", Pref);
end if;
end;
end if;
Next (Pack_Name);
end loop;
-- Loop through package names to mark all entities as potentially
-- use visible.
Pack_Name := First (Names (N));
while Present (Pack_Name) loop
if Is_Entity_Name (Pack_Name) then
Pack := Entity (Pack_Name);
if Ekind (Pack) /= E_Package and then Etype (Pack) /= Any_Type then
if Ekind (Pack) = E_Generic_Package then
Error_Msg_N -- CODEFIX
("a generic package is not allowed in a use clause",
Pack_Name);
elsif Ekind_In (Pack, E_Generic_Function, E_Generic_Package)
then
Error_Msg_N -- CODEFIX
("a generic subprogram is not allowed in a use clause",
Pack_Name);
elsif Ekind_In (Pack, E_Function, E_Procedure, E_Operator) then
Error_Msg_N -- CODEFIX
("a subprogram is not allowed in a use clause",
Pack_Name);
else
Error_Msg_N ("& is not allowed in a use clause", Pack_Name);
end if;
else
if Nkind (Parent (N)) = N_Compilation_Unit then
Check_In_Previous_With_Clause (N, Pack_Name);
end if;
if Applicable_Use (Pack_Name) then
Use_One_Package (Pack, N);
end if;
end if;
-- Report error because name denotes something other than a package
else
Error_Msg_N ("& is not a package", Pack_Name);
end if;
Next (Pack_Name);
end loop;
end Analyze_Use_Package;
----------------------
-- Analyze_Use_Type --
----------------------
procedure Analyze_Use_Type (N : Node_Id) is
E : Entity_Id;
Id : Node_Id;
begin
Set_Hidden_By_Use_Clause (N, No_Elist);
-- Chain clause to list of use clauses in current scope
if Nkind (Parent (N)) /= N_Compilation_Unit then
Chain_Use_Clause (N);
end if;
-- If the Used_Operations list is already initialized, the clause has
-- been analyzed previously, and it is begin reinstalled, for example
-- when the clause appears in a package spec and we are compiling the
-- corresponding package body. In that case, make the entities on the
-- existing list use_visible, and mark the corresponding types In_Use.
if Present (Used_Operations (N)) then
declare
Mark : Node_Id;
Elmt : Elmt_Id;
begin
Mark := First (Subtype_Marks (N));
while Present (Mark) loop
Use_One_Type (Mark, Installed => True);
Next (Mark);
end loop;
Elmt := First_Elmt (Used_Operations (N));
while Present (Elmt) loop
Set_Is_Potentially_Use_Visible (Node (Elmt));
Next_Elmt (Elmt);
end loop;
end;
return;
end if;
-- Otherwise, create new list and attach to it the operations that
-- are made use-visible by the clause.
Set_Used_Operations (N, New_Elmt_List);
Id := First (Subtype_Marks (N));
while Present (Id) loop
Find_Type (Id);
E := Entity (Id);
if E /= Any_Type then
Use_One_Type (Id);
if Nkind (Parent (N)) = N_Compilation_Unit then
if Nkind (Id) = N_Identifier then
Error_Msg_N ("type is not directly visible", Id);
elsif Is_Child_Unit (Scope (E))
and then Scope (E) /= System_Aux_Id
then
Check_In_Previous_With_Clause (N, Prefix (Id));
end if;
end if;
else
-- If the use_type_clause appears in a compilation unit context,
-- check whether it comes from a unit that may appear in a
-- limited_with_clause, for a better error message.
if Nkind (Parent (N)) = N_Compilation_Unit
and then Nkind (Id) /= N_Identifier
then
declare
Item : Node_Id;
Pref : Node_Id;
function Mentioned (Nam : Node_Id) return Boolean;
-- Check whether the prefix of expanded name for the type
-- appears in the prefix of some limited_with_clause.
---------------
-- Mentioned --
---------------
function Mentioned (Nam : Node_Id) return Boolean is
begin
return Nkind (Name (Item)) = N_Selected_Component
and then Chars (Prefix (Name (Item))) = Chars (Nam);
end Mentioned;
begin
Pref := Prefix (Id);
Item := First (Context_Items (Parent (N)));
while Present (Item) and then Item /= N loop
if Nkind (Item) = N_With_Clause
and then Limited_Present (Item)
and then Mentioned (Pref)
then
Change_Error_Text
(Get_Msg_Id, "premature usage of incomplete type");
end if;
Next (Item);
end loop;
end;
end if;
end if;
Next (Id);
end loop;
end Analyze_Use_Type;
--------------------
-- Applicable_Use --
--------------------
function Applicable_Use (Pack_Name : Node_Id) return Boolean is
Pack : constant Entity_Id := Entity (Pack_Name);
begin
if In_Open_Scopes (Pack) then
if Warn_On_Redundant_Constructs and then Pack = Current_Scope then
Error_Msg_NE -- CODEFIX
("& is already use-visible within itself?r?", Pack_Name, Pack);
end if;
return False;
elsif In_Use (Pack) then
Note_Redundant_Use (Pack_Name);
return False;
elsif Present (Renamed_Object (Pack))
and then In_Use (Renamed_Object (Pack))
then
Note_Redundant_Use (Pack_Name);
return False;
else
return True;
end if;
end Applicable_Use;
------------------------
-- Attribute_Renaming --
------------------------
procedure Attribute_Renaming (N : Node_Id) is
Loc : constant Source_Ptr := Sloc (N);
Nam : constant Node_Id := Name (N);
Spec : constant Node_Id := Specification (N);
New_S : constant Entity_Id := Defining_Unit_Name (Spec);
Aname : constant Name_Id := Attribute_Name (Nam);
Form_Num : Nat := 0;
Expr_List : List_Id := No_List;
Attr_Node : Node_Id;
Body_Node : Node_Id;
Param_Spec : Node_Id;
begin
Generate_Definition (New_S);
-- This procedure is called in the context of subprogram renaming, and
-- thus the attribute must be one that is a subprogram. All of those
-- have at least one formal parameter, with the exceptions of the GNAT
-- attribute 'Img, which GNAT treats as renameable.
if not Is_Non_Empty_List (Parameter_Specifications (Spec)) then
if Aname /= Name_Img then
Error_Msg_N
("subprogram renaming an attribute must have formals", N);
return;
end if;
else
Param_Spec := First (Parameter_Specifications (Spec));
while Present (Param_Spec) loop
Form_Num := Form_Num + 1;
if Nkind (Parameter_Type (Param_Spec)) /= N_Access_Definition then
Find_Type (Parameter_Type (Param_Spec));
-- The profile of the new entity denotes the base type (s) of
-- the types given in the specification. For access parameters
-- there are no subtypes involved.
Rewrite (Parameter_Type (Param_Spec),
New_Occurrence_Of
(Base_Type (Entity (Parameter_Type (Param_Spec))), Loc));
end if;
if No (Expr_List) then
Expr_List := New_List;
end if;
Append_To (Expr_List,
Make_Identifier (Loc,
Chars => Chars (Defining_Identifier (Param_Spec))));
-- The expressions in the attribute reference are not freeze
-- points. Neither is the attribute as a whole, see below.
Set_Must_Not_Freeze (Last (Expr_List));
Next (Param_Spec);
end loop;
end if;
-- Immediate error if too many formals. Other mismatches in number or
-- types of parameters are detected when we analyze the body of the
-- subprogram that we construct.
if Form_Num > 2 then
Error_Msg_N ("too many formals for attribute", N);
-- Error if the attribute reference has expressions that look like
-- formal parameters.
elsif Present (Expressions (Nam)) then
Error_Msg_N ("illegal expressions in attribute reference", Nam);
elsif
Nam_In (Aname, Name_Compose, Name_Exponent, Name_Leading_Part,
Name_Pos, Name_Round, Name_Scaling,
Name_Val)
then
if Nkind (N) = N_Subprogram_Renaming_Declaration
and then Present (Corresponding_Formal_Spec (N))
then
Error_Msg_N
("generic actual cannot be attribute involving universal type",
Nam);
else
Error_Msg_N
("attribute involving a universal type cannot be renamed",
Nam);
end if;
end if;
-- Rewrite attribute node to have a list of expressions corresponding to
-- the subprogram formals. A renaming declaration is not a freeze point,
-- and the analysis of the attribute reference should not freeze the
-- type of the prefix. We use the original node in the renaming so that
-- its source location is preserved, and checks on stream attributes are
-- properly applied.
Attr_Node := Relocate_Node (Nam);
Set_Expressions (Attr_Node, Expr_List);
Set_Must_Not_Freeze (Attr_Node);
Set_Must_Not_Freeze (Prefix (Nam));
-- Case of renaming a function
if Nkind (Spec) = N_Function_Specification then
if Is_Procedure_Attribute_Name (Aname) then
Error_Msg_N ("attribute can only be renamed as procedure", Nam);
return;
end if;
Find_Type (Result_Definition (Spec));
Rewrite (Result_Definition (Spec),
New_Occurrence_Of
(Base_Type (Entity (Result_Definition (Spec))), Loc));
Body_Node :=
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (
Make_Simple_Return_Statement (Loc,
Expression => Attr_Node))));
-- Case of renaming a procedure
else
if not Is_Procedure_Attribute_Name (Aname) then
Error_Msg_N ("attribute can only be renamed as function", Nam);
return;
end if;
Body_Node :=
Make_Subprogram_Body (Loc,
Specification => Spec,
Declarations => New_List,
Handled_Statement_Sequence =>
Make_Handled_Sequence_Of_Statements (Loc,
Statements => New_List (Attr_Node)));
end if;
-- In case of tagged types we add the body of the generated function to
-- the freezing actions of the type (because in the general case such
-- type is still not frozen). We exclude from this processing generic
-- formal subprograms found in instantiations.
-- We must exclude VM targets and restricted run-time libraries because
-- entity AST_Handler is defined in package System.Aux_Dec which is not
-- available in those platforms. Note that we cannot use the function
-- Restricted_Profile (instead of Configurable_Run_Time_Mode) because
-- the ZFP run-time library is not defined as a profile, and we do not
-- want to deal with AST_Handler in ZFP mode.
if VM_Target = No_VM
and then not Configurable_Run_Time_Mode
and then not Present (Corresponding_Formal_Spec (N))
and then Etype (Nam) /= RTE (RE_AST_Handler)
then
declare
P : constant Node_Id := Prefix (Nam);
begin
-- The prefix of 'Img is an object that is evaluated for each call
-- of the function that renames it.
if Aname = Name_Img then
Preanalyze_And_Resolve (P);
-- For all other attribute renamings, the prefix is a subtype
else
Find_Type (P);
end if;
-- If the target type is not yet frozen, add the body to the
-- actions to be elaborated at freeze time.
if Is_Tagged_Type (Etype (P))
and then In_Open_Scopes (Scope (Etype (P)))
then
Ensure_Freeze_Node (Etype (P));
Append_Freeze_Action (Etype (P), Body_Node);
else
Rewrite (N, Body_Node);
Analyze (N);
Set_Etype (New_S, Base_Type (Etype (New_S)));
end if;
end;
-- Generic formal subprograms or AST_Handler renaming
else
Rewrite (N, Body_Node);
Analyze (N);
Set_Etype (New_S, Base_Type (Etype (New_S)));
end if;
if Is_Compilation_Unit (New_S) then
Error_Msg_N
("a library unit can only rename another library unit", N);
end if;
-- We suppress elaboration warnings for the resulting entity, since
-- clearly they are not needed, and more particularly, in the case
-- of a generic formal subprogram, the resulting entity can appear
-- after the instantiation itself, and thus look like a bogus case
-- of access before elaboration.
Set_Suppress_Elaboration_Warnings (New_S);
end Attribute_Renaming;
----------------------
-- Chain_Use_Clause --
----------------------
procedure Chain_Use_Clause (N : Node_Id) is
Pack : Entity_Id;
Level : Int := Scope_Stack.Last;
begin
if not Is_Compilation_Unit (Current_Scope)
or else not Is_Child_Unit (Current_Scope)
then
null; -- Common case
elsif Defining_Entity (Parent (N)) = Current_Scope then
null; -- Common case for compilation unit
else
-- If declaration appears in some other scope, it must be in some
-- parent unit when compiling a child.
Pack := Defining_Entity (Parent (N));
if not In_Open_Scopes (Pack) then
null; -- default as well
-- If the use clause appears in an ancestor and we are in the
-- private part of the immediate parent, the use clauses are
-- already installed.
elsif Pack /= Scope (Current_Scope)
and then In_Private_Part (Scope (Current_Scope))
then
null;
else
-- Find entry for parent unit in scope stack
while Scope_Stack.Table (Level).Entity /= Pack loop
Level := Level - 1;
end loop;
end if;
end if;
Set_Next_Use_Clause (N,
Scope_Stack.Table (Level).First_Use_Clause);
Scope_Stack.Table (Level).First_Use_Clause := N;
end Chain_Use_Clause;
---------------------------
-- Check_Frozen_Renaming --
---------------------------
procedure Check_Frozen_Renaming (N : Node_Id; Subp : Entity_Id) is
B_Node : Node_Id;
Old_S : Entity_Id;
begin
if Is_Frozen (Subp) and then not Has_Completion (Subp) then
B_Node :=
Build_Renamed_Body
(Parent (Declaration_Node (Subp)), Defining_Entity (N));
if Is_Entity_Name (Name (N)) then
Old_S := Entity (Name (N));
if not Is_Frozen (Old_S)
and then Operating_Mode /= Check_Semantics
then
Append_Freeze_Action (Old_S, B_Node);
else
Insert_After (N, B_Node);
Analyze (B_Node);
end if;
if Is_Intrinsic_Subprogram (Old_S) and then not In_Instance then
Error_Msg_N
("subprogram used in renaming_as_body cannot be intrinsic",
Name (N));
end if;
else
Insert_After (N, B_Node);
Analyze (B_Node);
end if;
end if;
end Check_Frozen_Renaming;
-------------------------------
-- Set_Entity_Or_Discriminal --
-------------------------------
procedure Set_Entity_Or_Discriminal (N : Node_Id; E : Entity_Id) is
P : Node_Id;
begin
-- If the entity is not a discriminant, or else expansion is disabled,
-- simply set the entity.
if not In_Spec_Expression
or else Ekind (E) /= E_Discriminant
or else Inside_A_Generic
then
Set_Entity_With_Checks (N, E);
-- The replacement of a discriminant by the corresponding discriminal
-- is not done for a task discriminant that appears in a default
-- expression of an entry parameter. See Exp_Ch2.Expand_Discriminant
-- for details on their handling.
elsif Is_Concurrent_Type (Scope (E)) then
P := Parent (N);
while Present (P)
and then not Nkind_In (P, N_Parameter_Specification,
N_Component_Declaration)
loop
P := Parent (P);
end loop;
if Present (P)
and then Nkind (P) = N_Parameter_Specification
then
null;
else
Set_Entity (N, Discriminal (E));
end if;
-- Otherwise, this is a discriminant in a context in which
-- it is a reference to the corresponding parameter of the
-- init proc for the enclosing type.
else
Set_Entity (N, Discriminal (E));
end if;
end Set_Entity_Or_Discriminal;
-----------------------------------
-- Check_In_Previous_With_Clause --
-----------------------------------
procedure Check_In_Previous_With_Clause
(N : Node_Id;
Nam : Entity_Id)
is
Pack : constant Entity_Id := Entity (Original_Node (Nam));
Item : Node_Id;
Par : Node_Id;
begin
Item := First (Context_Items (Parent (N)));
while Present (Item) and then Item /= N loop
if Nkind (Item) = N_With_Clause
-- Protect the frontend against previous critical errors
and then Nkind (Name (Item)) /= N_Selected_Component
and then Entity (Name (Item)) = Pack
then
Par := Nam;
-- Find root library unit in with_clause
while Nkind (Par) = N_Expanded_Name loop
Par := Prefix (Par);
end loop;
if Is_Child_Unit (Entity (Original_Node (Par))) then
Error_Msg_NE ("& is not directly visible", Par, Entity (Par));
else
return;
end if;
end if;
Next (Item);
end loop;
-- On exit, package is not mentioned in a previous with_clause.
-- Check if its prefix is.
if Nkind (Nam) = N_Expanded_Name then
Check_In_Previous_With_Clause (N, Prefix (Nam));
elsif Pack /= Any_Id then
Error_Msg_NE ("& is not visible", Nam, Pack);
end if;
end Check_In_Previous_With_Clause;
---------------------------------
-- Check_Library_Unit_Renaming --
---------------------------------
procedure Check_Library_Unit_Renaming (N : Node_Id; Old_E : Entity_Id) is
New_E : Entity_Id;
begin
if Nkind (Parent (N)) /= N_Compilation_Unit then
return;
-- Check for library unit. Note that we used to check for the scope
-- being Standard here, but that was wrong for Standard itself.
elsif not Is_Compilation_Unit (Old_E)
and then not Is_Child_Unit (Old_E)
then
Error_Msg_N ("renamed unit must be a library unit", Name (N));
-- Entities defined in Standard (operators and boolean literals) cannot
-- be renamed as library units.
elsif Scope (Old_E) = Standard_Standard
and then Sloc (Old_E) = Standard_Location
then
Error_Msg_N ("renamed unit must be a library unit", Name (N));
elsif Present (Parent_Spec (N))
and then Nkind (Unit (Parent_Spec (N))) = N_Generic_Package_Declaration
and then not Is_Child_Unit (Old_E)
then
Error_Msg_N
("renamed unit must be a child unit of generic parent", Name (N));
elsif Nkind (N) in N_Generic_Renaming_Declaration
and then Nkind (Name (N)) = N_Expanded_Name
and then Is_Generic_Instance (Entity (Prefix (Name (N))))
and then Is_Generic_Unit (Old_E)
then
Error_Msg_N
("renamed generic unit must be a library unit", Name (N));
elsif Is_Package_Or_Generic_Package (Old_E) then
-- Inherit categorization flags
New_E := Defining_Entity (N);
Set_Is_Pure (New_E, Is_Pure (Old_E));
Set_Is_Preelaborated (New_E, Is_Preelaborated (Old_E));
Set_Is_Remote_Call_Interface (New_E,
Is_Remote_Call_Interface (Old_E));
Set_Is_Remote_Types (New_E, Is_Remote_Types (Old_E));
Set_Is_Shared_Passive (New_E, Is_Shared_Passive (Old_E));
end if;
end Check_Library_Unit_Renaming;
------------------------
-- Enclosing_Instance --
------------------------
function Enclosing_Instance return Entity_Id is
S : Entity_Id;