| ------------------------------------------------------------------------------ |
| -- -- |
| -- GNAT COMPILER COMPONENTS -- |
| -- -- |
| -- S E M _ A U X -- |
| -- -- |
| -- S p e c -- |
| -- -- |
| -- Copyright (C) 1992-2014, 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. -- |
| -- -- |
| -- As a special exception, if other files instantiate generics from this -- |
| -- unit, or you link this unit with other files to produce an executable, -- |
| -- this unit does not by itself cause the resulting executable to be -- |
| -- covered by the GNU General Public License. This exception does not -- |
| -- however invalidate any other reasons why the executable file might be -- |
| -- covered by the GNU Public License. -- |
| -- -- |
| -- GNAT was originally developed by the GNAT team at New York University. -- |
| -- Extensive contributions were provided by Ada Core Technologies Inc. -- |
| -- -- |
| ------------------------------------------------------------------------------ |
| |
| -- Package containing utility procedures used throughout the compiler, |
| -- and also by ASIS so dependencies are limited to ASIS included packages. |
| |
| -- Historical note. Many of the routines here were originally in Einfo, but |
| -- Einfo is supposed to be a relatively low level package dealing with the |
| -- content of entities in the tree, so this package is used for routines that |
| -- require more than minimal semantic knowledge. |
| |
| with Alloc; use Alloc; |
| with Namet; use Namet; |
| with Table; |
| with Types; use Types; |
| with Sinfo; use Sinfo; |
| |
| package Sem_Aux is |
| |
| -------------------------------- |
| -- Obsolescent Warnings Table -- |
| -------------------------------- |
| |
| -- This table records entities for which a pragma Obsolescent with a |
| -- message argument has been processed. |
| |
| type OWT_Record is record |
| Ent : Entity_Id; |
| -- The entity to which the pragma applies |
| |
| Msg : String_Id; |
| -- The string containing the message |
| end record; |
| |
| package Obsolescent_Warnings is new Table.Table ( |
| Table_Component_Type => OWT_Record, |
| Table_Index_Type => Int, |
| Table_Low_Bound => 0, |
| Table_Initial => Alloc.Obsolescent_Warnings_Initial, |
| Table_Increment => Alloc.Obsolescent_Warnings_Increment, |
| Table_Name => "Obsolescent_Warnings"); |
| |
| procedure Initialize; |
| -- Called at the start of compilation of each new main source file to |
| -- initialize the allocation of the Obsolescent_Warnings table. Note that |
| -- Initialize must not be called if Tree_Read is used. |
| |
| procedure Tree_Read; |
| -- Initializes Obsolescent_Warnings table from current tree file using the |
| -- relevant Table.Tree_Read routine. |
| |
| procedure Tree_Write; |
| -- Writes out Obsolescent_Warnings table to current tree file using the |
| -- relevant Table.Tree_Write routine. |
| |
| ----------------- |
| -- Subprograms -- |
| ----------------- |
| |
| function Ancestor_Subtype (Typ : Entity_Id) return Entity_Id; |
| -- The argument Id is a type or subtype entity. If the argument is a |
| -- subtype then it returns the subtype or type from which the subtype was |
| -- obtained, otherwise it returns Empty. |
| |
| function Available_View (Ent : Entity_Id) return Entity_Id; |
| -- Ent denotes an abstract state or a type that may come from a limited |
| -- with clause. Return the non-limited view of Ent if there is one or Ent |
| -- if this is not the case. |
| |
| function Constant_Value (Ent : Entity_Id) return Node_Id; |
| -- Ent is a variable, constant, named integer, or named real entity. This |
| -- call obtains the initialization expression for the entity. Will return |
| -- Empty for a deferred constant whose full view is not available or |
| -- in some other cases of internal entities, which cannot be treated as |
| -- constants from the point of view of constant folding. Empty is also |
| -- returned for variables with no initialization expression. |
| |
| function Corresponding_Unsigned_Type (Typ : Entity_Id) return Entity_Id; |
| -- Typ is a signed integer subtype. This routine returns the standard |
| -- unsigned type with the same Esize as the implementation base type of |
| -- Typ, e.g. Long_Integer => Long_Unsigned. |
| |
| function Enclosing_Dynamic_Scope (Ent : Entity_Id) return Entity_Id; |
| -- For any entity, Ent, returns the closest dynamic scope in which the |
| -- entity is declared or Standard_Standard for library-level entities. |
| |
| function First_Discriminant (Typ : Entity_Id) return Entity_Id; |
| -- Typ is a type with discriminants. The discriminants are the first |
| -- entities declared in the type, so normally this is equivalent to |
| -- First_Entity. The exception arises for tagged types, where the tag |
| -- itself is prepended to the front of the entity chain, so the |
| -- First_Discriminant function steps past the tag if it is present. |
| |
| function First_Stored_Discriminant (Typ : Entity_Id) return Entity_Id; |
| -- Typ is a type with discriminants. Gives the first discriminant stored |
| -- in an object of this type. In many cases, these are the same as the |
| -- normal visible discriminants for the type, but in the case of renamed |
| -- discriminants, this is not always the case. |
| -- |
| -- For tagged types, and untagged types which are root types or derived |
| -- types but which do not rename discriminants in their root type, the |
| -- stored discriminants are the same as the actual discriminants of the |
| -- type, and hence this function is the same as First_Discriminant. |
| -- |
| -- For derived untagged types that rename discriminants in the root type |
| -- this is the first of the discriminants that occur in the root type. To |
| -- be precise, in this case stored discriminants are entities attached to |
| -- the entity chain of the derived type which are a copy of the |
| -- discriminants of the root type. Furthermore their Is_Completely_Hidden |
| -- flag is set since although they are actually stored in the object, they |
| -- are not in the set of discriminants that is visible in the type. |
| -- |
| -- For derived untagged types, the set of stored discriminants are the real |
| -- discriminants from Gigi's standpoint, i.e. those that will be stored in |
| -- actual objects of the type. |
| |
| function First_Subtype (Typ : Entity_Id) return Entity_Id; |
| -- Applies to all types and subtypes. For types, yields the first subtype |
| -- of the type. For subtypes, yields the first subtype of the base type of |
| -- the subtype. |
| |
| function First_Tag_Component (Typ : Entity_Id) return Entity_Id; |
| -- Typ must be a tagged record type. This function returns the Entity for |
| -- the first _Tag field in the record type. |
| |
| function Get_Binary_Nkind (Op : Entity_Id) return Node_Kind; |
| -- Op must be an entity with an Ekind of E_Operator. This function returns |
| -- the Nkind value that would be used to construct a binary operator node |
| -- referencing this entity. It is an error to call this function if Ekind |
| -- (Op) /= E_Operator. |
| |
| function Get_Unary_Nkind (Op : Entity_Id) return Node_Kind; |
| -- Op must be an entity with an Ekind of E_Operator. This function returns |
| -- the Nkind value that would be used to construct a unary operator node |
| -- referencing this entity. It is an error to call this function if Ekind |
| -- (Op) /= E_Operator. |
| |
| function Get_Rep_Item |
| (E : Entity_Id; |
| Nam : Name_Id; |
| Check_Parents : Boolean := True) return Node_Id; |
| -- Searches the Rep_Item chain for a given entity E, for an instance of a |
| -- rep item (pragma, attribute definition clause, or aspect specification) |
| -- whose name matches the given name Nam. If Check_Parents is False then it |
| -- only returns rep item that has been directly specified for E (and not |
| -- inherited from its parents, if any). If one is found, it is returned, |
| -- otherwise Empty is returned. A special case is that when Nam is |
| -- Name_Priority, the call will also find Interrupt_Priority. |
| |
| function Get_Rep_Item |
| (E : Entity_Id; |
| Nam1 : Name_Id; |
| Nam2 : Name_Id; |
| Check_Parents : Boolean := True) return Node_Id; |
| -- Searches the Rep_Item chain for a given entity E, for an instance of a |
| -- rep item (pragma, attribute definition clause, or aspect specification) |
| -- whose name matches one of the given names Nam1 or Nam2. If Check_Parents |
| -- is False then it only returns rep item that has been directly specified |
| -- for E (and not inherited from its parents, if any). If one is found, it |
| -- is returned, otherwise Empty is returned. A special case is that when |
| -- one of the given names is Name_Priority, the call will also find |
| -- Interrupt_Priority. |
| |
| function Get_Rep_Pragma |
| (E : Entity_Id; |
| Nam : Name_Id; |
| Check_Parents : Boolean := True) return Node_Id; |
| -- Searches the Rep_Item chain for a given entity E, for an instance of a |
| -- representation pragma whose name matches the given name Nam. If |
| -- Check_Parents is False then it only returns representation pragma that |
| -- has been directly specified for E (and not inherited from its parents, |
| -- if any). If one is found and if it is the first rep item in the list |
| -- that matches Nam, it is returned, otherwise Empty is returned. A special |
| -- case is that when Nam is Name_Priority, the call will also find |
| -- Interrupt_Priority. |
| |
| function Get_Rep_Pragma |
| (E : Entity_Id; |
| Nam1 : Name_Id; |
| Nam2 : Name_Id; |
| Check_Parents : Boolean := True) return Node_Id; |
| -- Searches the Rep_Item chain for a given entity E, for an instance of a |
| -- representation pragma whose name matches one of the given names Nam1 or |
| -- Nam2. If Check_Parents is False then it only returns representation |
| -- pragma that has been directly specified for E (and not inherited from |
| -- its parents, if any). If one is found and if it is the first rep item in |
| -- the list that matches one of the given names, it is returned, otherwise |
| -- Empty is returned. A special case is that when one of the given names is |
| -- Name_Priority, the call will also find Interrupt_Priority. |
| |
| function Has_Rep_Item |
| (E : Entity_Id; |
| Nam : Name_Id; |
| Check_Parents : Boolean := True) return Boolean; |
| -- Searches the Rep_Item chain for the given entity E, for an instance of a |
| -- rep item (pragma, attribute definition clause, or aspect specification) |
| -- with the given name Nam. If Check_Parents is False then it only checks |
| -- for a rep item that has been directly specified for E (and not inherited |
| -- from its parents, if any). If found then True is returned, otherwise |
| -- False indicates that no matching entry was found. |
| |
| function Has_Rep_Item |
| (E : Entity_Id; |
| Nam1 : Name_Id; |
| Nam2 : Name_Id; |
| Check_Parents : Boolean := True) return Boolean; |
| -- Searches the Rep_Item chain for the given entity E, for an instance of a |
| -- rep item (pragma, attribute definition clause, or aspect specification) |
| -- with the given names Nam1 or Nam2. If Check_Parents is False then it |
| -- only checks for a rep item that has been directly specified for E (and |
| -- not inherited from its parents, if any). If found then True is returned, |
| -- otherwise False indicates that no matching entry was found. |
| |
| function Has_Rep_Pragma |
| (E : Entity_Id; |
| Nam : Name_Id; |
| Check_Parents : Boolean := True) return Boolean; |
| -- Searches the Rep_Item chain for the given entity E, for an instance of a |
| -- representation pragma with the given name Nam. If Check_Parents is False |
| -- then it only checks for a representation pragma that has been directly |
| -- specified for E (and not inherited from its parents, if any). If found |
| -- and if it is the first rep item in the list that matches Nam then True |
| -- is returned, otherwise False indicates that no matching entry was found. |
| |
| function Has_Rep_Pragma |
| (E : Entity_Id; |
| Nam1 : Name_Id; |
| Nam2 : Name_Id; |
| Check_Parents : Boolean := True) return Boolean; |
| -- Searches the Rep_Item chain for the given entity E, for an instance of a |
| -- representation pragma with the given names Nam1 or Nam2. If |
| -- Check_Parents is False then it only checks for a rep item that has been |
| -- directly specified for E (and not inherited from its parents, if any). |
| -- If found and if it is the first rep item in the list that matches one of |
| -- the given names then True is returned, otherwise False indicates that no |
| -- matching entry was found. |
| |
| function Has_External_Tag_Rep_Clause (T : Entity_Id) return Boolean; |
| -- Defined in tagged types. Set if an External_Tag rep. clause has been |
| -- given for this type. Use to avoid the generation of the default |
| -- External_Tag. |
| -- |
| -- Note: we used to use an entity flag for this purpose, but that was wrong |
| -- because it was not propagated from the private view to the full view. We |
| -- could have added that propagation, but it would have been an annoying |
| -- irregularity compared to other representation aspects, and the cost of |
| -- looking up the aspect when needed is small. |
| |
| function Has_Unconstrained_Elements (T : Entity_Id) return Boolean; |
| -- True if T has discriminants and is unconstrained, or is an array type |
| -- whose element type Has_Unconstrained_Elements. |
| |
| function Has_Variant_Part (Typ : Entity_Id) return Boolean; |
| -- Return True if the first subtype of Typ is a discriminated record type |
| -- which has a variant part. False otherwise. |
| |
| function In_Generic_Body (Id : Entity_Id) return Boolean; |
| -- Determine whether entity Id appears inside a generic body |
| |
| function Initialization_Suppressed (Typ : Entity_Id) return Boolean; |
| pragma Inline (Initialization_Suppressed); |
| -- Returns True if initialization should be suppressed for the given type |
| -- or subtype. This is true if Suppress_Initialization is set either for |
| -- the subtype itself, or for the corresponding base type. |
| |
| function Is_Body (N : Node_Id) return Boolean; |
| -- Determine whether an arbitrary node denotes a body |
| |
| function Is_By_Copy_Type (Ent : Entity_Id) return Boolean; |
| -- Ent is any entity. Returns True if Ent is a type entity where the type |
| -- is required to be passed by copy, as defined in (RM 6.2(3)). |
| |
| function Is_By_Reference_Type (Ent : Entity_Id) return Boolean; |
| -- Ent is any entity. Returns True if Ent is a type entity where the type |
| -- is required to be passed by reference, as defined in (RM 6.2(4-9)). |
| |
| function Is_Derived_Type (Ent : Entity_Id) return Boolean; |
| -- Determines if the given entity Ent is a derived type. Result is always |
| -- false if argument is not a type. |
| |
| function Is_Generic_Formal (E : Entity_Id) return Boolean; |
| -- Determine whether E is a generic formal parameter. In particular this is |
| -- used to set the visibility of generic formals of a generic package |
| -- declared with a box or with partial parameterization. |
| |
| function Is_Indefinite_Subtype (Ent : Entity_Id) return Boolean; |
| -- Ent is any entity. Determines if given entity is an unconstrained array |
| -- type or subtype, a discriminated record type or subtype with no initial |
| -- discriminant values or a class wide type or subtype and returns True if |
| -- so. False for other type entities, or any entities that are not types. |
| |
| function Is_Immutably_Limited_Type (Ent : Entity_Id) return Boolean; |
| -- Implements definition in Ada 2012 RM-7.5 (8.1/3). This differs from the |
| -- following predicate in that an untagged record with immutably limited |
| -- components is NOT by itself immutably limited. This matters, e.g. when |
| -- checking the legality of an access to the current instance. |
| |
| function Is_Limited_View (Ent : Entity_Id) return Boolean; |
| -- Ent is any entity. True for a type that is "inherently" limited (i.e. |
| -- cannot become nonlimited). From the Ada 2005 RM-7.5(8.1/2), "a type with |
| -- a part that is of a task, protected, or explicitly limited record type". |
| -- These are the types that are defined as return-by-reference types in Ada |
| -- 95 (see RM95-6.5(11-16)). In Ada 2005, these are the types that require |
| -- build-in-place for function calls. Note that build-in-place is allowed |
| -- for other types, too. This is also used for identifying pure procedures |
| -- whose calls should not be eliminated (RM 10.2.1(18/2)). |
| |
| function Is_Limited_Type (Ent : Entity_Id) return Boolean; |
| -- Ent is any entity. Returns true if Ent is a limited type (limited |
| -- private type, limited interface type, task type, protected type, |
| -- composite containing a limited component, or a subtype of any of |
| -- these types). This older routine overlaps with the previous one, this |
| -- should be cleaned up??? |
| |
| function Nearest_Ancestor (Typ : Entity_Id) return Entity_Id; |
| -- Given a subtype Typ, this function finds out the nearest ancestor from |
| -- which constraints and predicates are inherited. There is no simple link |
| -- for doing this, consider: |
| -- |
| -- subtype R is Integer range 1 .. 10; |
| -- type T is new R; |
| -- |
| -- In this case the nearest ancestor is R, but the Etype of T'Base will |
| -- point to R'Base, so we have to go rummaging in the declarations to get |
| -- this information. It is used for making sure we freeze this before we |
| -- freeze Typ, and also for retrieving inherited predicate information. |
| -- For the case of base types or first subtypes, there is no useful entity |
| -- to return, so Empty is returned. |
| -- |
| -- Note: this is similar to Ancestor_Subtype except that it also deals |
| -- with the case of derived types. |
| |
| function Nearest_Dynamic_Scope (Ent : Entity_Id) return Entity_Id; |
| -- This is similar to Enclosing_Dynamic_Scope except that if Ent is itself |
| -- a dynamic scope, then it is returned. Otherwise the result is the same |
| -- as that returned by Enclosing_Dynamic_Scope. |
| |
| function Next_Tag_Component (Tag : Entity_Id) return Entity_Id; |
| -- Tag must be an entity representing a _Tag field of a tagged record. |
| -- The result returned is the next _Tag field in this record, or Empty |
| -- if this is the last such field. |
| |
| function Number_Discriminants (Typ : Entity_Id) return Pos; |
| -- Typ is a type with discriminants, yields number of discriminants in type |
| |
| function Object_Type_Has_Constrained_Partial_View |
| (Typ : Entity_Id; |
| Scop : Entity_Id) return Boolean; |
| -- Return True if type of object has attribute Has_Constrained_Partial_View |
| -- set to True; in addition, within a generic body, return True if subtype |
| -- of the object is a descendant of an untagged generic formal private or |
| -- derived type, and the subtype is not an unconstrained array subtype |
| -- (RM 3.3(23.10/3)). |
| |
| function Ultimate_Alias (Prim : Entity_Id) return Entity_Id; |
| pragma Inline (Ultimate_Alias); |
| -- Return the last entity in the chain of aliased entities of Prim. If Prim |
| -- has no alias return Prim. |
| |
| function Unit_Declaration_Node (Unit_Id : Entity_Id) return Node_Id; |
| -- Unit_Id is the simple name of a program unit, this function returns the |
| -- corresponding xxx_Declaration node for the entity. Also applies to the |
| -- body entities for subprograms, tasks and protected units, in which case |
| -- it returns the subprogram, task or protected body node for it. The unit |
| -- may be a child unit with any number of ancestors. |
| |
| function Package_Specification (Pack_Id : Entity_Id) return Node_Id; |
| -- Given an entity for a package or generic package, return corresponding |
| -- package specification. Simplifies handling of child units, and better |
| -- than the old idiom: Specification (Unit_Declaration_Node (Pack_Id)). |
| |
| end Sem_Aux; |
