gcc/ada/sem_ch3.ads

   1 ------------------------------------------------------------------------------
   2 --                                                                          --
   3 --                         GNAT COMPILER COMPONENTS                         --
   4 --                                                                          --
   5 --                              S E M _ C H 3                               --
   6 --                                                                          --
   7 --                                 S p e c                                  --
   8 --                                                                          --
   9 --          Copyright (C) 1992-2005, Free Software Foundation, Inc.         --
  10 --                                                                          --
  11 -- GNAT is free software;  you can  redistribute it  and/or modify it under --
  12 -- terms of the  GNU General Public License as published  by the Free Soft- --
  13 -- ware  Foundation;  either version 2,  or (at your option) any later ver- --
  14 -- sion.  GNAT is distributed in the hope that it will be useful, but WITH- --
  15 -- OUT ANY WARRANTY;  without even the  implied warranty of MERCHANTABILITY --
  16 -- or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License --
  17 -- for  more details.  You should have  received  a copy of the GNU General --
  18 -- Public License  distributed with GNAT;  see file COPYING.  If not, write --
  19 -- to  the  Free Software Foundation,  51  Franklin  Street,  Fifth  Floor, --
  20 -- Boston, MA 02110-1301, USA.                                              --
  21 --                                                                          --
  22 -- GNAT was originally developed  by the GNAT team at  New York University. --
  23 -- Extensive contributions were provided by Ada Core Technologies Inc.      --
  24 --                                                                          --
  25 ------------------------------------------------------------------------------
  26
  27 with Nlists; use Nlists;
  28 with Types;  use Types;
  29
  30 package Sem_Ch3  is
  31    procedure Analyze_Component_Declaration              (N : Node_Id);
  32    procedure Analyze_Incomplete_Type_Decl               (N : Node_Id);
  33    procedure Analyze_Itype_Reference                    (N : Node_Id);
  34    procedure Analyze_Number_Declaration                 (N : Node_Id);
  35    procedure Analyze_Object_Declaration                 (N : Node_Id);
  36    procedure Analyze_Others_Choice                      (N : Node_Id);
  37    procedure Analyze_Private_Extension_Declaration      (N : Node_Id);
  38    procedure Analyze_Subtype_Declaration                (N : Node_Id);
  39    procedure Analyze_Subtype_Indication                 (N : Node_Id);
  40    procedure Analyze_Type_Declaration                   (N : Node_Id);
  41    procedure Analyze_Variant_Part                       (N : Node_Id);
  42
  43    function Access_Definition
  44      (Related_Nod : Node_Id;
  45       N           : Node_Id) return Entity_Id;
  46    --  An access definition defines a general access type for a formal
  47    --  parameter.  The procedure is called when processing formals, when
  48    --  the current scope is the subprogram. The Implicit type is attached
  49    --  to the Related_Nod put into the enclosing scope, so that the only
  50    --  entities defined in the spec are the formals themselves.
  51
  52    procedure Access_Subprogram_Declaration
  53      (T_Name : Entity_Id;
  54       T_Def  : Node_Id);
  55    --  The subprogram specification yields the signature of an implicit
  56    --  type, whose Ekind is Access_Subprogram_Type. This implicit type is
  57    --  the designated type of the declared access type. In subprogram calls,
  58    --  the signature of the implicit type works like the profile of a regular
  59    --  subprogram.
  60
  61    procedure Analyze_Declarations (L : List_Id);
  62    --  Called to analyze a list of declarations (in what context ???). Also
  63    --  performs necessary freezing actions (more description needed ???)
  64
  65    procedure Analyze_Interface_Declaration (T : Entity_Id; Def : Node_Id);
  66    --  Analyze an interface declaration or a formal interface declaration
  67
  68    procedure Analyze_Per_Use_Expression (N : Node_Id; T : Entity_Id);
  69    --  Default and per object expressions do not freeze their components,
  70    --  and must be analyzed and resolved accordingly. The analysis is
  71    --  done by calling the Pre_Analyze_And_Resolve routine and setting
  72    --  the global In_Default_Expression flag. See the documentation section
  73    --  entitled "Handling of Default and Per-Object Expressions" in sem.ads
  74    --  for details. N is the expression to be analyzed, T is the expected type.
  75
  76    procedure Array_Type_Declaration (T : in out Entity_Id; Def : Node_Id);
  77    --  Process an array type declaration. If the array is constrained, we
  78    --  create an implicit parent array type, with the same index types and
  79    --  component type.
  80
  81    procedure Access_Type_Declaration (T : Entity_Id; Def : Node_Id);
  82    --  Process an access type declaration
  83
  84    procedure Check_Abstract_Overriding (T : Entity_Id);
  85    --  Check that all abstract subprograms inherited from T's parent type
  86    --  have been overridden as required, and that nonabstract subprograms
  87    --  have not been incorrectly overridden with an abstract subprogram.
  88
  89    procedure Check_Aliased_Component_Types (T : Entity_Id);
  90    --  Given an array type or record type T, check that if the type is
  91    --  nonlimited, then the nominal subtype of any components of T
  92    --  that have discriminants must be constrained.
  93
  94    procedure Check_Completion (Body_Id : Node_Id := Empty);
  95    --  At the end of a declarative part, verify that all entities that
  96    --  require completion have received one. If Body_Id is absent, the
  97    --  error indicating a missing completion is placed on the declaration
  98    --  that needs completion. If Body_Id is present, it is the defining
  99    --  identifier of a package body, and errors are posted on that node,
 100    --  rather than on the declarations that require completion in the package
 101    --  declaration.
 102
 103    procedure Collect_Interfaces
 104      (N            : Node_Id;
 105       Derived_Type : Entity_Id);
 106    --  Ada 2005 (AI-251): Subsidiary procedure to Build_Derived_Record_Type
 107    --  and Analyze_Formal_Interface_Type.
 108    --  Collect the list of interfaces that are not already implemented by the
 109    --  ancestors. This is the list of interfaces for which we must provide
 110    --  additional tag components.
 111
 112    procedure Derive_Subprogram
 113      (New_Subp     : in out Entity_Id;
 114       Parent_Subp  : Entity_Id;
 115       Derived_Type : Entity_Id;
 116       Parent_Type  : Entity_Id;
 117       Actual_Subp  : Entity_Id := Empty);
 118    --  Derive the subprogram Parent_Subp from Parent_Type, and replace the
 119    --  subsidiary subtypes with the derived type to build the specification
 120    --  of the inherited subprogram (returned in New_Subp). For tagged types,
 121    --  the derived subprogram is aliased to that of the actual (in the
 122    --  case where Actual_Subp is nonempty) rather than to the corresponding
 123    --  subprogram of the parent type.
 124
 125    procedure Derive_Subprograms
 126      (Parent_Type           : Entity_Id;
 127       Derived_Type          : Entity_Id;
 128       Generic_Actual        : Entity_Id := Empty;
 129       No_Predefined_Prims   : Boolean   := False);
 130    --  To complete type derivation, collect/retrieve the primitive operations
 131    --  of the parent type, and replace the subsidiary subtypes with the derived
 132    --  type, to build the specs of the inherited ops. For generic actuals, the
 133    --  mapping of the primitive operations to those of the parent type is also
 134    --  done by rederiving the operations within the instance. For tagged types,
 135    --  the derived subprograms are aliased to those of the actual, not those of
 136    --  the ancestor. The last two params are used in case of derivation from
 137    --  abstract interface types: No_Predefined_Prims is used to avoid the
 138    --  derivation of predefined primitives from an abstract interface.
 139    --
 140    --  Note: one might expect this to be private to the package body, but
 141    --  there is one rather unusual usage in package Exp_Dist.
 142
 143    function Find_Type_Of_Subtype_Indic (S : Node_Id) return Entity_Id;
 144    --  Given a subtype indication S (which is really an N_Subtype_Indication
 145    --  node or a plain N_Identifier), find the type of the subtype mark.
 146
 147    function Find_Type_Name (N : Node_Id) return Entity_Id;
 148    --  Enter the identifier in a type definition, or find the entity already
 149    --  declared, in the case of the full declaration of an incomplete or
 150    --  private type.
 151
 152    function Get_Discriminant_Value
 153      (Discriminant       : Entity_Id;
 154       Typ_For_Constraint : Entity_Id;
 155       Constraint         : Elist_Id) return Node_Id;
 156    --  ??? MORE DOCUMENTATION
 157    --  Given a discriminant somewhere in the Typ_For_Constraint tree
 158    --  and a Constraint, return the value of that discriminant.
 159
 160    function Is_Null_Extension (T : Entity_Id) return Boolean;
 161    --  Returns True if the tagged type T has an N_Full_Type_Declaration that
 162    --  is a null extension, meaning that it has an extension part without any
 163    --  components and does not have a known discriminant part.
 164
 165    function Is_Visible_Component (C : Entity_Id) return Boolean;
 166    --  Determines if a record component C is visible in the present context.
 167    --  Note that even though component C could appear in the entity chain
 168    --  of a record type, C may not be visible in the current context. For
 169    --  instance, C may be a component inherited in the full view of a private
 170    --  extension which is not visible in the current context.
 171
 172    procedure Make_Index
 173      (I            : Node_Id;
 174       Related_Nod  : Node_Id;
 175       Related_Id   : Entity_Id := Empty;
 176       Suffix_Index : Nat := 1);
 177    --  Process an index that is given in an array declaration, an entry
 178    --  family declaration or a loop iteration. The index is given by an
 179    --  index declaration (a 'box'), or by a discrete range. The later can
 180    --  be the name of a discrete type, or a subtype indication.
 181    --  Related_Nod is the node where the potential generated implicit types
 182    --  will be inserted. The 2 last parameters are used for creating the name.
 183
 184    procedure Make_Class_Wide_Type (T : Entity_Id);
 185    --  A Class_Wide_Type is created for each tagged type definition. The
 186    --  attributes of a class wide type are inherited from those of the type
 187    --  T. If T is introduced by a private declaration, the corresponding
 188    --  class wide type is created at the same time, and therefore there is
 189    --  a private and a full declaration for the class wide type type as well.
 190
 191    procedure Process_Full_View (N : Node_Id; Full_T, Priv_T : Entity_Id);
 192    --  Process some semantic actions when the full view of a private type is
 193    --  encountered and analyzed. The first action is to create the full views
 194    --  of the dependant private subtypes. The second action is to recopy the
 195    --  primitive operations of the private view (in the tagged case).
 196    --  N is the N_Full_Type_Declaration node.
 197
 198    --    Full_T is the full view of the type whose full declaration is in N.
 199    --
 200    --    Priv_T is the private view of the type whose full declaration is in N.
 201
 202    procedure Process_Range_Expr_In_Decl
 203      (R           : Node_Id;
 204       T           : Entity_Id;
 205       Check_List  : List_Id := Empty_List;
 206       R_Check_Off : Boolean := False);
 207    --  Process a range expression that appears in a declaration context. The
 208    --  range is analyzed and resolved with the base type of the given type,
 209    --  and an appropriate check for expressions in non-static contexts made
 210    --  on the bounds. R is analyzed and resolved using T, so the caller should
 211    --  if necessary link R into the tree before the call, and in particular in
 212    --  the case of a subtype declaration, it is appropriate to set the parent
 213    --  pointer of R so that the types get properly frozen. The Check_List
 214    --  parameter is used when the subprogram is called from
 215    --  Build_Record_Init_Proc and is used to return a set of constraint
 216    --  checking statements generated by the Checks package. R_Check_Off is
 217    --  set to True when the call to Range_Check is to be skipped.
 218
 219    function Process_Subtype
 220      (S           : Node_Id;
 221       Related_Nod : Node_Id;
 222       Related_Id  : Entity_Id := Empty;
 223       Suffix      : Character := ' ') return Entity_Id;
 224    --  Process a subtype indication S and return corresponding entity.
 225    --  Related_Nod is the node where the potential generated implicit types
 226    --  will be inserted. The Related_Id and Suffix parameters are used to
 227    --  build the associated Implicit type name.
 228
 229    procedure Process_Discriminants
 230      (N    : Node_Id;
 231       Prev : Entity_Id := Empty);
 232    --  Process the discriminants contained in an N_Full_Type_Declaration or
 233    --  N_Incomplete_Type_Decl node N. If the declaration is a completion,
 234    --  Prev is entity on the partial view, on which references are posted.
 235
 236    function Replace_Anonymous_Access_To_Protected_Subprogram
 237      (N      : Node_Id;
 238       Prev_E : Entity_Id) return Entity_Id;
 239    --  Ada 2005 (AI-254): Create and decorate an internal full type declaration
 240    --  in the enclosing scope corresponding to an anonymous access to protected
 241    --  subprogram. In addition, replace the anonymous access by an occurrence
 242    --  of this internal type. Prev_Etype is used to link the new internal
 243    --  entity with the anonymous entity. Return the entity of this type
 244    --  declaration.
 245
 246    procedure Set_Completion_Referenced (E : Entity_Id);
 247    --  If E is the completion of a private or incomplete  type declaration,
 248    --  or the completion of a deferred constant declaration, mark the entity
 249    --  as referenced. Warnings on unused entities, if needed, go on the
 250    --  partial view.
 251
 252 end Sem_Ch3;