------------------------------------------------------------------------------ -- -- -- GNAT COMPILER COMPONENTS -- -- -- -- S E M _ C H 3 -- -- -- -- S p e c -- -- -- -- Copyright (C) 1992-2012, 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 Nlists; use Nlists; with Types; use Types; package Sem_Ch3 is procedure Analyze_Component_Declaration (N : Node_Id); procedure Analyze_Full_Type_Declaration (N : Node_Id); procedure Analyze_Incomplete_Type_Decl (N : Node_Id); procedure Analyze_Itype_Reference (N : Node_Id); procedure Analyze_Number_Declaration (N : Node_Id); procedure Analyze_Object_Declaration (N : Node_Id); procedure Analyze_Others_Choice (N : Node_Id); procedure Analyze_Private_Extension_Declaration (N : Node_Id); procedure Analyze_Subtype_Indication (N : Node_Id); procedure Analyze_Variant_Part (N : Node_Id); procedure Analyze_Subtype_Declaration (N : Node_Id; Skip : Boolean := False); -- Called to analyze a subtype declaration. The parameter Skip is used for -- Ada 2005 (AI-412). We set to True in order to avoid reentering the -- defining identifier of N when analyzing a rewritten incomplete subtype -- declaration. function Access_Definition (Related_Nod : Node_Id; N : Node_Id) return Entity_Id; -- An access definition defines a general access type for a formal -- parameter. The procedure is called when processing formals, when -- the current scope is the subprogram. The Implicit type is attached -- to the Related_Nod put into the enclosing scope, so that the only -- entities defined in the spec are the formals themselves. procedure Access_Subprogram_Declaration (T_Name : Entity_Id; T_Def : Node_Id); -- The subprogram specification yields the signature of an implicit -- type, whose Ekind is Access_Subprogram_Type. This implicit type is -- the designated type of the declared access type. In subprogram calls, -- the signature of the implicit type works like the profile of a regular -- subprogram. procedure Add_Internal_Interface_Entities (Tagged_Type : Entity_Id); -- Add to the list of primitives of Tagged_Type the internal entities -- associated with covered interface primitives. These entities link the -- interface primitives with the tagged type primitives that cover them. procedure Analyze_Declarations (L : List_Id); -- Called to analyze a list of declarations (in what context ???). Also -- performs necessary freezing actions (more description needed ???) procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id); -- Analyze an interface declaration or a formal interface declaration procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id); -- Process an array type declaration. If the array is constrained, we -- create an implicit parent array type, with the same index types and -- component type. procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id); -- Process an access type declaration procedure Build_Itype_Reference (Ityp : Entity_Id; Nod : Node_Id); -- Create a reference to an internal type, for use by Gigi. The back-end -- elaborates itypes on demand, i.e. when their first use is seen. This can -- lead to scope anomalies if the first use is within a scope that is -- nested within the scope that contains the point of definition of the -- itype. The Itype_Reference node forces the elaboration of the itype -- in the proper scope. The node is inserted after Nod, which is the -- enclosing declaration that generated Ityp. -- -- A related mechanism is used during expansion, for itypes created in -- branches of conditionals. See Ensure_Defined in exp_util. -- Could both mechanisms be merged ??? procedure Check_Abstract_Overriding (T : Entity_Id); -- Check that all abstract subprograms inherited from T's parent type have -- been overridden as required, and that nonabstract subprograms have not -- been incorrectly overridden with an abstract subprogram. procedure Check_Aliased_Component_Types (T : Entity_Id); -- Given an array type or record type T, check that if the type is -- nonlimited, then the nominal subtype of any components of T that -- have discriminants must be constrained. procedure Check_Completion (Body_Id : Node_Id := Empty); -- At the end of a declarative part, verify that all entities that require -- completion have received one. If Body_Id is absent, the error indicating -- a missing completion is placed on the declaration that needs completion. -- If Body_Id is present, it is the defining identifier of a package body, -- and errors are posted on that node, rather than on the declarations that -- require completion in the package declaration. procedure Check_CPP_Type_Has_No_Defaults (T : Entity_Id); -- Check that components of imported CPP type T do not have default -- expressions because the constructor (if any) is on the C++ side. procedure Derive_Subprogram (New_Subp : in out Entity_Id; Parent_Subp : Entity_Id; Derived_Type : Entity_Id; Parent_Type : Entity_Id; Actual_Subp : Entity_Id := Empty); -- Derive the subprogram Parent_Subp from Parent_Type, and replace the -- subsidiary subtypes with the derived type to build the specification -- of the inherited subprogram (returned in New_Subp). For tagged types, -- the derived subprogram is aliased to that of the actual (in the -- case where Actual_Subp is nonempty) rather than to the corresponding -- subprogram of the parent type. procedure Derive_Subprograms (Parent_Type : Entity_Id; Derived_Type : Entity_Id; Generic_Actual : Entity_Id := Empty); -- To complete type derivation, collect/retrieve the primitive operations -- of the parent type, and replace the subsidiary subtypes with the derived -- type, to build the specs of the inherited ops. For generic actuals, the -- mapping of the primitive operations to those of the parent type is also -- done by rederiving the operations within the instance. For tagged types, -- the derived subprograms are aliased to those of the actual, not those of -- the ancestor. -- -- Note: one might expect this to be private to the package body, but there -- is one rather unusual usage in package Exp_Dist. function Find_Hidden_Interface (Src : Elist_Id; Dest : Elist_Id) return Entity_Id; -- Ada 2005: Determine whether the interfaces in list Src are all present -- in the list Dest. Return the first differing interface, or Empty -- otherwise. function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id; -- Given a subtype indication S (which is really an N_Subtype_Indication -- node or a plain N_Identifier), find the type of the subtype mark. function Find_Type_Name (N : Node_Id) return Entity_Id; -- Enter the identifier in a type definition, or find the entity already -- declared, in the case of the full declaration of an incomplete or -- private type. If the previous declaration is tagged then the class-wide -- entity is propagated to the identifier to prevent multiple incompatible -- class-wide types that may be created for self-referential anonymous -- access components. function Get_Discriminant_Value (Discriminant : Entity_Id; Typ_For_Constraint : Entity_Id; Constraint : Elist_Id) return Node_Id; -- ??? MORE DOCUMENTATION -- Given a discriminant somewhere in the Typ_For_Constraint tree and a -- Constraint, return the value of that discriminant. function Is_Constant_Bound (Exp : Node_Id) return Boolean; -- Exp is the expression for an array bound. Determines whether the -- bound is a compile-time known value, or a constant entity, or an -- enumeration literal, or an expression composed of constant-bound -- subexpressions which are evaluated by means of standard operators. function Is_Null_Extension (T : Entity_Id) return Boolean; -- Returns True if the tagged type T has an N_Full_Type_Declaration that -- is a null extension, meaning that it has an extension part without any -- components and does not have a known discriminant part. function Is_Visible_Component (C : Entity_Id) return Boolean; -- Determines if a record component C is visible in the present context. -- Note that even though component C could appear in the entity chain -- of a record type, C may not be visible in the current context. For -- instance, C may be a component inherited in the full view of a private -- extension which is not visible in the current context. procedure Make_Index (I : Node_Id; Related_Nod : Node_Id; Related_Id : Entity_Id := Empty; Suffix_Index : Nat := 1; In_Iter_Schm : Boolean := False); -- Process an index that is given in an array declaration, an entry -- family declaration or a loop iteration. The index is given by an -- index declaration (a 'box'), or by a discrete range. The later can -- be the name of a discrete type, or a subtype indication. -- -- Related_Nod is the node where the potential generated implicit types -- will be inserted. The next last parameters are used for creating the -- name. In_Iter_Schm is True if Make_Index is called on the discrete -- subtype definition in an iteration scheme. procedure Make_Class_Wide_Type (T : Entity_Id); -- A Class_Wide_Type is created for each tagged type definition. The -- attributes of a class-wide type are inherited from those of the type T. -- If T is introduced by a private declaration, the corresponding class -- wide type is created at the same time, and therefore there is a private -- and a full declaration for the class-wide type as well. function OK_For_Limited_Init_In_05 (Typ : Entity_Id; Exp : Node_Id) return Boolean; -- Presuming Exp is an expression of an inherently limited type Typ, -- returns True if the expression is allowed in an initialization context -- by the rules of Ada 2005. We use the rule in RM-7.5(2.1/2), "...it is an -- aggregate, a function_call, or a parenthesized expression or qualified -- expression whose operand is permitted...". Note that in Ada 95 mode, -- we sometimes wish to give warnings based on whether the program _would_ -- be legal in Ada 2005. Note that Exp must already have been resolved, -- so we can know whether it's a function call (as opposed to an indexed -- component, for example). In the case where Typ is a limited interface's -- class-wide type, then the expression is allowed to be of any kind if its -- type is a nonlimited descendant of the interface. function OK_For_Limited_Init (Typ : Entity_Id; Exp : Node_Id) return Boolean; -- Always False in Ada 95 mode. Equivalent to OK_For_Limited_Init_In_05 in -- Ada 2005 mode. procedure Preanalyze_Spec_Expression (N : Node_Id; T : Entity_Id); -- Default and per object expressions do not freeze their components, and -- must be analyzed and resolved accordingly. The analysis is done by -- calling the Preanalyze_And_Resolve routine and setting the global -- In_Default_Expression flag. See the documentation section entitled -- "Handling of Default and Per-Object Expressions" in sem.ads for full -- details. N is the expression to be analyzed, T is the expected type. -- This mechanism is also used for aspect specifications that have an -- expression parameter that needs similar preanalysis. procedure Preanalyze_Assert_Expression (N : Node_Id; T : Entity_Id); -- Wrapper on Preanalyze_Spec_Expression for assertion expressions, so that -- In_Assertion_Expr can be properly adjusted. procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id); -- Process some semantic actions when the full view of a private type is -- encountered and analyzed. The first action is to create the full views -- of the dependant private subtypes. The second action is to recopy the -- primitive operations of the private view (in the tagged case). -- N is the N_Full_Type_Declaration node. -- -- Full_T is the full view of the type whose full declaration is in N. -- -- Priv_T is the private view of the type whose full declaration is in N. procedure Process_Range_Expr_In_Decl (R : Node_Id; T : Entity_Id; Check_List : List_Id := Empty_List; R_Check_Off : Boolean := False; In_Iter_Schm : Boolean := False); -- Process a range expression that appears in a declaration context. The -- range is analyzed and resolved with the base type of the given type, and -- an appropriate check for expressions in non-static contexts made on the -- bounds. R is analyzed and resolved using T, so the caller should if -- necessary link R into the tree before the call, and in particular in the -- case of a subtype declaration, it is appropriate to set the parent -- pointer of R so that the types get properly frozen. Check_List is used -- when the subprogram is called from Build_Record_Init_Proc and is used to -- return a set of constraint checking statements generated by the Checks -- package. R_Check_Off is set to True when the call to Range_Check is to -- be skipped. In_Iter_Schm is True if Process_Range_Expr_In_Decl is called -- on the discrete subtype definition in an iteration scheme. function Process_Subtype (S : Node_Id; Related_Nod : Node_Id; Related_Id : Entity_Id := Empty; Suffix : Character := ' ') return Entity_Id; -- Process a subtype indication S and return corresponding entity. -- Related_Nod is the node where the potential generated implicit types -- will be inserted. The Related_Id and Suffix parameters are used to -- build the associated Implicit type name. procedure Process_Discriminants (N : Node_Id; Prev : Entity_Id := Empty); -- Process the discriminants contained in an N_Full_Type_Declaration or -- N_Incomplete_Type_Decl node N. If the declaration is a completion, -- Prev is entity on the partial view, on which references are posted. -- However, note that Process_Discriminants is called for a completion only -- if partial view had no discriminants (else we just check conformance -- between the two views and do not call Process_Discriminants again for -- the completion). function Replace_Anonymous_Access_To_Protected_Subprogram (N : Node_Id) return Entity_Id; -- Ada 2005 (AI-254): Create and decorate an internal full type declaration -- for an anonymous access to protected subprogram. For a record component -- declaration, the type is created in the enclosing scope, for an array -- type declaration or an object declaration it is simply placed ahead of -- this declaration. procedure Set_Completion_Referenced (E : Entity_Id); -- If E is the completion of a private or incomplete type declaration, -- or the completion of a deferred constant declaration, mark the entity -- as referenced. Warnings on unused entities, if needed, go on the -- partial view. end Sem_Ch3;